Booming markets for Moroccan argan oil appear tobenefit some rural households while threateningthe endemic argan forestTravis J Lybberta1 Abdellah Aboudrareb Deborah Chaloudc Nicholas Magnand and Maliha Nashc

aAgricultural and Resource Economics University of California Davis CA 95616 bMachinisme Agricole Eacutecole Nationale drsquoAgriculture Meknegraves Morocco50000 cLandscape Ecology Branch United States Environmental Protection Agency Las Vegas NV 89119 and dEnvironment and Production TechnologyDivision International Food Policy Research Institute Washington DC 20006

Edited by Christopher B Barrett Cornell University Ithaca NY and accepted by the Editorial Board June 22 2011 (received for review April 20 2011)

Moroccorsquos argan oil is now the most expensive edible oil in theworld High-value argan markets have sparked a bonanza of arganactivity Nongovernmental organizations international and domes-tic development agencies and argan oil cooperatives aggressivelypromote thewinndashwin aimof simultaneously benefiting local peopleand the health of the argan forest This paper tests some of thesewinndashwin claims Analysis of a panel of detailed household datasuggests that the boom has enabled some rural households to in-crease consumption increase their goat herds (which bodes poorlyfor the argan forest) and send their girls to secondary school Theboom has predictably made households vigilant guardians of fruiton the tree but it has not incited investments in longer term treeand forest health We evaluate landscape-level impacts of thesechanges using commune-level data on educational enrollmentand normalized difference vegetation index data over the periodfrom 1981 to 2009 The results of the mesoanalysis of enrollmentare consistent with the microanalysis the argan boom seems tohave improved educational outcomes especially for girls Our nor-malized difference vegetation index analysis however suggeststhat booming argan prices have not improved the forest and mayhave even induced degradation We conclude by exploring the dy-namic interactions between argan markets local institutions ruralhousehold welfare and forest conservation and sustainability

poverty | biodiversity | nontimber forest products | normalized differencevegetation index | development economics

At $300L or more argan oil is currently the worldrsquos mostexpensive edible oil For cosmetic uses it demands an even

higher price and it is the subject of several US and Europeancosmetic patents (1) The oil which has been a mainstay for theBerber people of southwestern Morocco for centuries was pro-pelled out of obscurity in the 1990s by favorable findings about itsculinary cosmetic and evenmedicinal virtues Since 1999 rapidlyappreciating prices in high-value markets have sparked a bonanzaof argan activity Nongovernmental organizations internationaland domestic development agencies and argan oil cooperativeshave played a central role in this bonanza with the dual aim ofalleviating rural poverty and inciting local conservation of theendemic argan tree Both goals are worthwhile poverty and il-literacy are relatively high in the region (2) and the argan treewhich has defied domestication (3) acts as foundation species forover 1200 other species of plants and animals (140 endemic) inthe ecoregion (4ndash7) Evidence of this ecological uniqueness is thatthe argan forest was designated as a United Nations EducationalScientific and Cultural Organization Biosphere Reserve in 1998(8) Winndashwin claims of poverty alleviation and biodiversity con-servation now appear on virtually every argan product label andhave been showcased by media outlets worldwide Using a com-bination of household- and landscape-level analyses we evaluatethese now common argan claimsAlthough the recent boom in argan prices has its roots in the

unique properties of argan oil and the rarity of the endemic argan

tree (SI Discussion) attempts to induce local biodiversity con-servation through new high-value markets for nontimber forestproducts are now quite common Conservation through com-mercialization (9) has however come under increasing scrutinyby researchers and policymakers in the past decade (10 11)Conceptually several conditions must hold before commerciali-zation can be expected to induce conservation gains (12) Localbenefits must be sufficient to induce behavioral changes Condi-tional on sufficient local benefits welfare and biodiversity impactsdepend on regeneration properties (13 14) property rights reg-imens within indigenous communities (10 15 16) sovereigntyover the resource (17) and how households invest benefits thatthey reap (18)Two linkages between biodiversity and poverty traps guide our

analysis First the argan case showcases several common linkagesbetween forest product commercialization and poverty dynamicsBecause the rural poor often rely disproportionately on forestproductsmdashtypically extracted through open or common accessrightsmdashthey are frequently targeted by conservation throughcommercialization efforts Empirical evidence of impacts onpoverty and inequality has been somewhat encouraging (19ndash21)but in some contexts dependence on low-return forest productsby those people who have limited livelihood options may resultin a poverty trap particularly in cases where commercializationbrings resource degradation (11 22ndash24) Forest products oftenfunction as an important safety net by helping vulnerable house-holds cope with hard times and thereby may prevent householdsfrom slipping farther into poverty but it may be difficult for suchhouseholds to leverage forest products as a means of accumu-lating the assets needed to shift to higher-return pursuits (21)Furthermore even the safety net benefit can be compromised ifcommercialization depletes forest resources leaving vulnerablehouseholds more susceptible to adverse shocks that can drivethem deeper into poverty (24)Second argan activities are traditionally the domain of women

suggesting that the argan boom could provide a sex-specific rem-edy to persistent poverty When women benefit outcomes forchildrenmdashalong with prospects for future poverty alleviationmdashim-prove (25) Specifically higher argan product valuesmight increasesthe returns to female labor improve womenrsquos position in intra-household bargaining (26) and heighten their social status (27)However an increase in returns to female unskilled labor could alsoincrease the opportunity cost of female education diverting girlsrsquo

Author contributions TJL designed research TJL AA and NM performed researchTJL AA DC NM and MN analyzed data and TJL DC NM and MN wrote thepaper

The authors declare no conflict of interest

This article is a PNAS Direct Submission CBB is a guest editor invited by the EditorialBoard1To whom correspondence should be addressed E-mail tlybbertucdavisedu

This article contains supporting information online at wwwpnasorglookupsuppldoi101073pnas1106382108-DCSupplemental

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time from school to argan production and perpetuating the povertycycle (28) In this paper we evaluate these linkages between bio-diversity and persistent rural poverty in the argan region

ResultsIn this section we first synthesize results from a recent micro-analysis of the local impacts of the argan oil boom on how ruralhouseholds interact with argan markets what benefits arise fromtheir market participation and how their use of the forest hasevolved (29) Building on this microanalysis we present theresults of mesoanalyses that test the winndashwin claims at a moreaggregated landscape level

Local Impacts on Rural Households and the Forest As described indetail elsewhere (29) we use panel household data fromEssaouira Province to assess the impact of the argan boom onhouseholds and their exploitation of the forest (Fig S1) Asargan prices soared between 1999 and 2007 average householdargan oil production tripled and average argan oil consumptionfell by one-half Argan fruit became a popular speculative in-vestment with average household stocks increasing 10-foldThe proportion of households selling argan oil more than dou-bled however the proportion selling fruit increased more thansixfold because the booming fruit market has turned argan fruitinto an important source of income Even more recently mar-kets for argan kernels began to emerge and these markets in-creasingly enable locals to capture the greater value added bystripping pulp and cracking stones to extract the kernelWe compare several measurable indicators of welfare among

rural households before and after dramatic changes in arganmarkets We use householdsrsquo access to argan fruit in 1999 asa measure of how much they stood to benefit from the ensuingappreciation of argan prices First we find that householdswith access to more fruit enjoyed a slightly higher increase inhousehold consumption relative to other households Secondbenefiting households accumulated more assets in the form ofgoats (but not other livestock) this finding bodes poorly forthe forest because goats often climb in trees to graze leaveswith negative impacts on forest health and subsequent harvestsThird girls from households that stood to benefit from boomingargan prices were significantly more likely to make the transitionfrom primary to secondary school than girls from other house-holds but no such result is apparent for boysdagger

The boom has also induced households to alter their exploi-tation of the forest Conflicts over argan resources have in-creased as well as conflicts over permanent barriers aroundseasonal usufruct forest tracts (SI Discussion and Fig S2) Al-though most households still graze their goats in argan treesduring some periods of the year they do so less frequently thanbeforemdashand very rarely during the fruit collection season Localstend to harvest argan fruit more aggressively and often use sticksto dislodge fruit which can damage branches and dislodge budsfor subsequent yearrsquos production Despite higher fruit priceslocals have shifted away from butane and to dead argan wood asa source of energyDagger Whereas 17 of our households relied

primarily on argan wood for cooking in 1999 67 relied pri-marily on argan wood for cooking in 2007 With steadily in-creasing costs of living and stagnating income outside the argansector households are increasingly choosing to substitute freeargan wood for purchased butane In sum microlevel evidencesuggests that the boom is benefiting some locals but it has al-tered forest exploitation by increasing short-run fruit collectionincentives rather than long-run concerns of forest sustainability

Landscape-Level Impacts We next zoom out and assess the impactof booming argan markets on the region and forest landscape Todo this analysis we focus our attention on aggregate welfare dataat the commune level for one province and on satellite image dataat the 8 times 8-km level for the entire region (Fig S1) To evaluatethe association between the argan boom and the response inwelfare and forest changes we follow a dosendashresponse approachthat uses booming argan prices after 1999 as the treatment andargan forest coverage as the dosage of this treatment Using theonly available panel data on welfare outcomes at the communelevel we focus our mesoanalysis of welfare impacts on educationenrollment data from Essouira Province The results (Table 1)suggest that the argan boom has had a positive impact on studentenrollment in communes where educational infrastructure isweak This effect is particularly strong for girls Among com-munes with weak educational infrastructure those communeswith 65 argan forest cover saw the proportion of eligible girlsenrolled increase by roughly 10 between 2000 and 2005sect

Next we analyze satellite data to assess landscape-level trendsin the density of the argan forest and forest canopy By comparingthese trends before and after the onset of the boom in 1999 weevaluate whether high-value argan commercialization has led toimprovements in forest and canopy density We quantify thesedensity changes using the normalized difference vegetation index(NDVI) (32ndash36) which is used to monitor vegetation cover plantbiomass productivity and biodiversity in many settings (37) Tovalidate our use of this measure we compared NDVI with per-cent canopy measures based on recent satellite images taken inthe argan region (SI Discussion) The correlation between dryseason NDVI and canopy cover is high (gt090) because trees areoften the only dry season vegetation in the region In the analysiswe control for current and cumulative rainfall to isolate anthro-pogenic impacts on NDVI and exploit the fact that forest floor islargely void of vegetation during the dry season to isolate theNDVI trend for the forest canopy We display these condition-al dry season NDVI trends pixel by pixel in Fig 1 A positive(negative) conditional trend indicates a thickening (thinning) ofthe forest canopy net of rainfall effectspara Before the boom neg-ative trends prevailed in some portions of the southern arganforest because of dramatic expansions of irrigated agriculture inthat region during the 1980s and 1990s (38 39) Since the boombegan much of the northern argan forest appears to have thin-ned Because the northern forest has attracted greater attentionduring the argan boom because of its proximity to major marketsand popularity among tourists this pattern seems consistent withthe boom negatively affecting the forest but we must push moreto statistically test the impact of the boom

Argan fruit can be stored for many years without deteriorating the quality of oil ex-tracted from the kernel Even under ideal conditionsmdashcool and darkmdashhowever arganoil can oxidize rapidly

daggerMost rural villages including those villages in our sample have easy access to a localprimary school but secondary schools are farther away therefore the transition fromprimary to secondary school requires a substantial investment Although 47 of girlsand 67 of boys in rural areas attend primary school only 8 of girls and 17 of boysattend secondary school (30)

DaggerCutting live argan trees and branches is illegal The argan wood used as a fuel source ismostly collected as dead or dying branches which may be more readily available withmore aggressive harvesting techniques Although concrete evidence is obviously sparseanecdotal evidence suggests that at least some of this collected argan wood is not dead

sectThe 240-point estimate from Table 1 indicates the increase in girlsrsquo enrollment as a per-centage of the total population School-aged (5ndash19 y) girls constitute roughly 16 of thetotal Moroccan population (31) We can adjust the point estimate to approximate theincrease in girlsrsquo enrollment as a percentage of school-aged girls as 0024016 = 15Relative to a commune with no argan forest one with 65 coverage thus experiencedroughly a 10 increase in girlsrsquo enrollment

paraLocal exploitation through overgrazing and urban encroachment in a few locations isthe most likely cause of any negative canopy trends Although irrigated agricultureexpanded in some southern portions of the forest before the argan boom it has af-fected the argan forest much less in recent years

13964 | wwwpnasorgcgidoi101073pnas1106382108 Lybbert et al

To this end we zoom in on pixels in or near the argan forestand assess changes in canopy trends in greater detail As beforewe use the argan boom as the treatment where only pixels with(preboom) argan forest coverage are treated Nonargan pixelsthat contain different tree and shrub species (eg Acacia Juni-perus and Tetraclinis) serve as pseudocontrol pixels because theywere subject to the same climatic pressures as the argan forestbut not the anthropogenic changes induced by the argan boomAfter differencing the estimated pre- and post-1999 canopytrends for each pixel we compare trend changes for argan andnonargan pixels (Fig S3) We match argan forest pixels withsimilar nonargan forest pixels nearby and estimate the averageeffect of the argan boom on (treated) argan forest canopy basedon the pairwise comparison of these matched pixelsk Althoughthere is some variation in statistical significance across differentmatching configurations (Table 2) pixels treated with boomingargan prices experienced a decline in NDVI relative to similarpixels with nonargan tree and shrub species Because we areinterested in testing the impact of the argan boom on the arganforest (and not its impact on nonargan forest were it converted toargan forest) the average treatment effect on the treated is mostrelevant and is significant for all of our matching configurationsBoth the magnitude and significance of these impacts are greaterwhen we match pixels with more than 40 argan cover to those

pixels with nonargan forest Booming argan markets have cer-tainly not improved the argan forest and may have even inducedmore degradation particularly in northern locationsThese household- and landscape-level analyses offer comple-

mentary tests of the winndashwin claims of poverty alleviation andbiodiversity conservation The household data allow for rigoroustests of welfare impacts but evidence of forest impacts can onlybe deduced from householdsrsquo reported actions In contrast thelandscape-level analysis offers less robust but suggestive evidenceof benefits to girlsrsquo education while providing a more rigoroustest of the impact of the boom on the argan forest Combinedthese results suggest that locals are benefiting from the arganboom in ways that may improve womenrsquos welfare and alleviatepersistent rural poverty but this benefit is at the risk of degradingthe forest and the biodiversity that it sustains Unless localsrsquoshort-term obsession with fruit collection matures into longer-term productivity and sustainability concerns rural poverty re-duction may itself be a short-term benefit of the argan boom

Discussion Dynamic Dimensions of Local Welfare and ForestImpactsThe argan oil case offers an excellent opportunity to investigatethe dynamic linkages between local benefits and conservationgains Consider the interplay between localsrsquo response to arganfruit price appreciation argan markets and forest impacts In1999 high-value argan oil extractors insisted on purchasing only

Table 1 Results of primary and secondary school enrollment estimation for rural communes inEssaouira Province from 2000 to 2005

1-y difference 4-y difference

Girls Boys Total Girls Boys Total

ArganCoefficients minus0052 minus029 minus033 minus022 minus118 minus133P value 064 00068 0053 064 0021 0094

Argan times weak education infrastructureCoefficients 059 046 104 240 183 423P value 00038 0075 0019 00052 0090 0024

Argan times weak other infrastructureCoefficients 0040 011 014 016 045 057P value 059 019 031 060 025 037

Weak education infrastructure indexCoefficients minus0066 minus0061 minus013 minus027 minus025 minus051P value 0085 016 0079 0100 018 0091

Weak other infrastructure indexCoefficients minus0034 00087 minus0027 minus013 0035 minus0091P value 034 082 070 039 083 076

TrendCoefficients minus036 minus019 minus056P value 0000 0000 0000

ConstantCoefficients 7248 3779 11162 044 059 102P value 0000 0000 0000 0000 0000 0000

N 179 179 178 44 44 43R2 047 015 040 018 020 019

The dependent variable is the change in the number of students enrolled in both primary and secondaryschools as a percent of commune population (measured in percentage points) Weak education and otherinfrastructures are constructed as factor analytic indexes using commune-level access to education accessibilitythrough different forms of transportation and access to electricity and running water The SEs used to computethe P values were clustered at the commune level Note that 2- and 3-y differences yield similar results

kWe have performed an additional analysis that offers a complementary perspective onthese trend changes and yields qualitatively consistent results For example we havepooled the trend changes for all pixels and estimated a spatial error regression modelwith percent argan cover and other controls as explanatory variables The coefficient onpercent argan cover is negativemdashindicating that a higher dosage of argan cover isassociated with a more negative trend change during the argan boommdashand weaklystatistically significant (P value = 015)

Note that whereas Fig 1 displays the value of the NDVI trend coefficient Table 2 isbased on the difference in this trend before and after the onset of the boom Thusalthough Fig 1 suggests that negative NDVI trends have been spatially concentrated inthe northern forest since the onset of the boom Table 2 suggests that the change intrends has been negative on average in the argan forest relative to nonargan forest

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whole fruit in local markets as a guarantee that the kernel insidehad not passed through a goatrsquos gut (40) Since then rapid ap-preciation of argan fruit prices has prompted locals to collectfruit by hand and prevent their goats from ingesting whole fruitThus there are far fewer goat kernels in local markets Knowingthis fact high-value extractors are increasingly willing to pur-chase kernels in spot markets which have become nearly asactive as those markets for argan fruit Moreover this change hasincreased the volume of kernels sold as well as doubled the pricepremium of kernels over fruit between 2005 and 2009daggerdagger In shortinitial market changes induced a behavioral response that re-solved a market for lemons problem (41) and enabled theemergence of high-value kernel markets Because the laborioustask of extracting the kernel has yet to be mechanized this in-duced kernel market may be the most promising path from high-value argan markets to rural poverty alleviationNext consider the dynamic pressures on tenure institutions in

the argan region Booming argan markets have not surprisinglyled to greater privatization pressure (11 42) In the argan forestunique tenurial arrangements (SI Discussion and Fig S2) giveimportant nuance to implications of these privatization pres-sures Households that previously only had seasonal usufructrights to specific tracts of the forests are now enclosing thesetracts to deny others access all year long These barriers whichare technically allowed if temporary are becoming increasinglypermanent Because private usufruct rights encroach on collec-tive grazing rights during the nonharvest season the forest maywell benefit from better managementmdashalbeit at the cost ofexcluding poor households with limited private productiveresources from these forest commons The poverty of thesehouseholds may persist despite booming argan marketsFrom a conservation perspective a key dynamic involves the

apparent mismatch between localsrsquo conservation incentives andthe long-run sustainability of the argan forest Although localsare now less likely to let their goats browse in the tree canopythis forest-friendly change is motivated more by immediateconcerns about the fruit harvest than by any longer-term concernfor tree or forest productivity Goats still regularly climb andbrowse trees outside the fruit harvest season when most trees

are treated as an open access resource and therefore theycontinue to tax the forest Ever-growing goat herds thus remaina concern This mismatch between private incentives and sus-tainability of the forest not only bodes poorly for the argan forestin general but interacts with drought cycles and more aggressivefruit harvesting in potentially negative ways Although the argantree is well-adapted to arid conditions and can survive in a dor-mant state for several years during extreme drought it is quitevulnerable during lesser drought conditions that do not triggerthis dormant response Locals and their goats generally exploitthe argan tree more heavily during such episodes of moderatedrought because other options dry up before the argan tree goesdormantmdasha dependence that can only increase as householdsshift their livelihoods more heavily to argan fruit As fruit pro-duction falls during these periods harvesting tactics are likelybecoming even more aggressive Precisely this scenario playedout in 2008mdasha year of low fruit production high fruit pricesconflicts among collectors and frequent and aggressive fruitharvesting Although the argan tree is robust to many pressuresrecovery from these episodes of intense climatic and exploitationpressures can be painfully slow Because it serves as foundationspecies for over 1200 species (7) this cyclical and intensifyingpressure on the argan tree threatens the broader biodiversity ofthe AcaciandashArgania ecoregion

Materials and MethodsWe surveyed a representative sample of rural households in Essouira Provincein 1999 and again in 2007 (Fig S1) Analysis of the 1999 data collected beforethe argan boom suggested that differentiation in argan oil markets wouldprevent locals from tapping high-value markets directly (40) and that con-servation gains might be disappointing because the slow growth of the treeimplies low returns to local conservation investments (43) We compare our1999 and 2007 data to evaluate the welfare effects of induced changes inhouseholdsrsquo argan activities Specifically we assess how householdsrsquo accessto argan fruit in 1999mdashan indicator of ex ante potential to benefit from theargan boommdashaffected three types of household welfare outcomes con-sumption (spending at market) assets (livestock holdings) and childrenrsquoseducation (complete details in ref 29)

Our broader mesolevel analysis exploits differences in forest coverageacross communes and pixels to assess the impact of the argan boom ontwo response variables changes in educational outcomes and forest can-opy density As the treatment we use booming argan markets after 1999Initial argan forest coverage (as collected in a 1994 Moroccan forest in-ventory) indicates the dosage of the argan boom treatment in a given-location

In the commune-level education analysis we use primary and secondaryschool enrollment data from Essaouira Province disaggregated by sex andcollected annually from 2000 to 2005 a period of rapid appreciation in arganprices that roughly corresponds to our household-level data Althoughwe can

Before boom began

(lt1999)

After boom began

(gt=1999)

Net Forest Canopy Trend

Negative (plt015)

Positive (plt015)

Fig 1 Estimated pixel-level trends for dry season NDVI net of rainfall effects Because trees are often the only dry season vegetation these dry season NDVItrends track forest canopy changes Left shows these trends before the argan boom started (ie before uses years 1981ndash1998) Right shows these trends afterthe argan boom started (ie after uses 1999ndash2009) Negative and positive net forest canopy trends are shown for statistically significant trend coefficientsPixels with insignificant trend coefficients are depicted as blank Cross-hatching indicates the extent of the argan forest in 1994

daggerdaggerThis price premium for kernels over fruit is driven by two countervailing factors First itis positive because of the value added from kernel extraction an onerous task that iscarried out by women and has yet to be mechanized very successfully The second andcountervailing pressure is the risk that kernels have been digested by a goat whichreduces the premium of kernels over fruit As goat-ingested kernels become morescarce in local markets this second risk penalty diminishes and the kernelpremium increases

13966 | wwwpnasorgcgidoi101073pnas1106382108 Lybbert et al

measure the transition from primary to secondary school for each child in oursurveyed households we can only measure total enrollment by sex with thecommune data because these data do not distinguish between primary andsecondary students We regress changes in enrollment as a percentage ofcommunepopulation on the percent of the commune covered by argan forestin1994 twocommune-level infrastructure indexes interaction termsbetweenforest cover and infrastructure indexes and a time trend We construct theinfrastructure indexes using factor analysis (SI Materials and Methods) andinclude them as controls because rural enrollment decisions are heavilyshaped by accessibility to schools and geographic isolation (eg accessibilityby different forms of transportation availability of electricity etc) Further-more the impact of argan benefits on these enrollment decisions may varyaccording to local infrastructure increased household income may partlycompensate for weak infrastructure and therefore could have a biggermarginal impact on enrollment in places with poor infrastructure To testwhether the enrollment impact of the argan boom is mediated by infra-structure we include the interaction of argan cover and these indexes in ourspecification We estimate this model separately by sex for 1- and 4-y en-rollment differences The lack of similar panel data prevents us from con-ducting this kind of commune-level analysis for other provinces in the arganregion or using measures of household consumption poverty or livestock asdependent variables

We use our NDVI analysis to evaluate anthropogenic changes in forestand canopy density caused primarily by local exploitation of the forest es-pecially grazing Based on the validation exercise described in SI Materialsand Methods we are confident that NDVI is a robust measure of canopycoverage (Table S1) We compare changes in the argan forest to changesover the same time period in nearby nonargan forest using an empiricalmodel that is relevant to argan trees nonargan trees and shrubs alikemdashallof which function as foundation species in very similar ecosystems Our ap-proach relies on NDVI differencing which has been shown to measurelandscape changes in regions more arid and more sparsely vegetated thanthe argan forest (44 45) In contrast to earlier work that assessed changesthroughout Morocco using NDVI (46) we focus on the argan forest regionincorporate rainfall data and isolate the NDVI trend for the forest canopy byfocusing on dry season trends during which there is virtually no vegetationbesides tree canopies The data that we use consist of 10-d composite NDVIdata covering 29 y (1981ndash2009) which have a resolution of 8 times 8 km andwere derived from advanced very high-resolution radiometer available fromthe US Geological Survey (47) The data were based on composite imagesgenerated by the National Oceanic and Atmospheric Administration As inother settings (37) we expect the NDVI to be strongly correlated with spe-cies richness and biomass in the argan forest region because in the dryseason it reflects forest and canopy density of foundation species in theseecosystems

In the arid argan forest region rainfall is critically important to vegetativeproductivity On average over 90 of precipitation in the region falls duringthe wet season between November 1 and May 31 Although the forest floorcan produce various grasses and rain-fed farmers can grow a meager barleycrop during these months the floor of the forestmdashwhether argan or non-arganmdashis largely void of vegetation during the dry season We leverage thefact that trees and shrubs are the only vegetation in the forest during thedry season to isolate the NDVI trend for the forest canopy Specifically weestimate an autoregressive switching regression model for each pixel thattakes the following form (Eqs 1 and 2)

NDVIit frac14 β0 thorn β1Rainit thorn β2CumRainit thornWetiethβ3tTHORN

thornDryiβ4CumRainit minus 1 thorn θt

thorn εit and

εit frac14PKsfrac141

ρsεiminus s thorn uit

[1 and 2]

where Rainit is contemporaneous rainfall measured at a provincial weatherstation for the 10-d period t and season i CumRain is cumulative rainfallsince the beginning of the last wet season Wet and Dry are wet and dryseason dummies respectively and t is a trend variable In this specificationthe switching regression on trend enables us to focus specifically on the dryseason trend (θ) while controlling for factors that affect NDVI in both sea-sons as well as season-specific factors such as lagged cumulative rainfallwhich directly affects the forest canopy During the dry season vegetationcaptured by the NDVI is contained almost entirely in the forest canopyand therefore θ specifically captures changes in the forest canopy We usea stepwise procedure to determine the order of autoregression Given thedistinct seasonality of rainfall in the region this procedure yields a highorder of autoregression (K = 39) The complete time series includes over800 observations for each of 7765 pixels We use the onset of the boomin 1999 to split this data into preboom and boom phases and estimatethe dry season trend over these two sets of years for each pixel separately(Fig 1)

To formally test how the boom has affected the argan forest we use thetwo estimated trend coefficients for each pixel to construct a differentialtrend variable Δbθz frac14 bθge 1999

z minusbθlt 1999

z which captures the change in the esti-mated canopy trend for pixel z associated with the onset of the argan boomin 1999DaggerDagger Next we compare Δbθz for each pixel in the argan forest to one in

Table 2 Average treatment effects for the presence of argan forest on the change in dry season NDVI trend sincethe onset of the argan market boom

1 2 3 4 5 6

Exclude pixels below median argan cover No No No Yes Yes YesWeights on matching covariatesdagger Equal Proximity Proximity Equal Proximity ProximityExclude lowest 25 of mean dry (NDVI)Dagger No No Yes No No YesAverage treatment effect

Coefficients minus00040 minus00027 minus00028 minus00050 minus00056 minus00064P value 0046 017 019 0030 0014 0011

Average treatment effect on treatedCoefficients minus00051 minus00043 minus00044 minus00078 minus00074 minus00080P value 0033 0067 0086 0008 0008 0007

n 493 493 444 335 335 302

These estimates are based on nearest-neighbor matching using geographic proximity mean dry season NDVI and coefficient ofvariation of NDVI as matching covariates P values are based on heteroskedastic SEsPercent argan cover indicates the amount covered by argan forest as indicated by the 1994 argan forest inventory Note that thismeasurement is the extent but not the density of the argan forest Among pixels with any argan cover median percent argan cover is40 Matching treated argan pixels with more than 40 argan forest cover with control pixels with nonargan forest provide a cleanercomparison of argan and nonargan forest pixelsdaggerEqual indicates nearest-neighbor matching with equal weights on all matching covariate Proximity indicates matching with heavierweight on geographic proximity than on mean dry season NDVI and coefficient of variation (NDVI)DaggerLow mean dry season NDVI indicates little or no tree and shrub coverage whether argan or nonargan Excluding the lowest quartile ofpixels based on mean dry season NDVI effectively excludes nonforested or sparsely forested pixels

DaggerDaggerGraphically bθlt1999z indicates the linear slope of the forest canopy from 1981 to 1998

(conditional on all other variables in Eqs 1 and 2) and bθ ge1999z is the conditional slope of

the canopy from 1999 to 2009 Δbθz frac14 bθ ge1999z minusbθlt1999

z thus indicates the change in slopebetween these two periods (ie before and during the argan boom)

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similar and nearby nonargan forest drawn from pixels adjacent to the arganforest Because the pixels in each of these pairs are subject to comparableclimatic and other pressuressectsect but only the argan pixel is affected bybooming argan marketsparapara we can pool all these pairwise comparisons to-gether to estimate an average treatment effect of the argan boom on theargan forest (Table 2)

Before matching argan and nonargan pixels we exclude pixels that in-clude irrigated land and urban fringes We use nearest-neighbor matchingbased on geographic proximity mean dry season NDVI and the coefficient ofvariation of NDVI This matching process pairs pixels in the argan forest with

nearby pixels with other tree and shrub species that otherwise have similarvegetative density We use these matched pairs to estimate the averagetreatment effect of the argan boom on argan forest density using thenonargan pixels with other species as controls The average treatment effecton the treated indicates the impact of the argan boom on the argan forestrelative to its impact on nonargan forest Because this test is a relative test itcaptures genuine improvements in argan forest displaced degradation innonargan forest or both whichmakes finding a positive (negative) impact ofbooming argan markets on argan forest easier (harder) For example if localson the edge of the argan forest move their livestock to the nonargan forest inthe wake of rapid argan price appreciation to increase their fruit collectionthis increased pressure would decrease the nonargan forest canopy trendrelative to the neighboring argan forest As one of the three robustnesstests in Table 2 we estimate treatment effects excluding pixels with sparsetree or shrub cover (ie those pixels in the lowest quantile of mean dryseason NDVI) Notice Although this work was reviewed by EPA and ap-proved for publication it may not necessarily reflect official agency policyMention of trade names or commercial products does not constitute en-dorsement or recommendation for use

1 Lybbert TJ (2007) Patent disclosure requirements and benefit sharing A counterfac-tual case of Moroccorsquos argan oil Ecol Econ 6412ndash18

2 Lanjouw P (2004) The Geography of Poverty in Morocco Micro-Level Estimates ofPoverty and Inequality from Combined Census and Household Survey Data (WorldBank Washington DC)

3 Nouaim R Mangin G Breuil M Chaussod R (2002) The argan tree (Argania spinosa) inMorocco Propagation by seeds cuttings and in-vitro techniques Agrofor Syst 5471ndash81

4 Msanda F El Aboudi A Peltier J (2005) Biodiversity and biogeography of Moroccanargan tree communities Cahiers Agricultures 14357ndash364

5 World Wildlife Fund McGinley M (2007) Mediterranean acacia-argania dry wood-lands and succulent thickets Mediterranean acacia-argania dry woodlands and suc-culent thickets Encyclopedia of Earth ed Cleveland CJ (National Council for Scienceand the Environment Washington DC)

6 Peltier J (1983) Les seacuteries de lrsquoarganeraie steppique dans le Souss (Maroc) EcologiaMediterranea 977ndash88

7 Aymerich M Tarrier M (2010) Un Deacutesert Plein de Vie (Carnets de Voyages Naturalistesau Maroc Saharien La Croisee de Chemins Morocco)

8 Fasskaoui B (2009) Fonctions deacutefis et enjeux de la gestion et du deacuteveloppementdurables dans la Reacuteserve de Biosphegravere de lrsquoArganeraie (Maroc) Eacutetudes Caribeacuteennes12 Available at httpetudescaribeennesrevuesorg3711 Accessed July 13 2011

9 Evans MI (1993) Conservation by commercialization Tropical Forests People andFood Biocultural Interactions and Applications to Development eds Hladik CM et al(Parthenon Publishing Group Pearl River NY) pp 815ndash822

10 Arnold JEM Perez MR (2001) Can non-timber forest products match tropical forestconservation and development objectives Ecol Econ 39437ndash447

11 Neumann RP Hirsch E (2000) Commercialisation of Non-Timber Forest Products Re-view and Analysis of Research (Food and Agriculture Organization Rome) ppviiindash176

12 Barrett CB Lybbert TJ (2000) Is bioprospecting a viable strategy for conservingtropical ecosystems Ecol Econ 34293ndash300

13 Peters CM (1994) Sustainable Harvest of Non-Timber Plant Resources in Tropical MoistForest An Ecological Primer (Biodiversity Support Program Washington DC) ppxixndash45

14 Witkowski ETF Lamont BB Obbens FJ (1994) Commercial picking of Banksia hook-eriana in the wild reduces subsequent shoot flower and seed production J Appl Ecol31508ndash520

15 Lopez-Feldman A Wilen J-E (2008) Poverty and spatial dimensions of non-timberforest extraction Environ Dev Econ 13621ndash642

16 Ostrom E Gardner R Walker J (1994) Rules Games and Common-Pool Resources(University of Michigan Press Ann Arbor MI) pp xvindash369

17 Dove MR (1993) A revisionist view of tropical deforestation and development Envi-ron Conserv 2017ndash24

18 Escobal J Aldana U (2003) Are nontimber forest products the antidote to rainforestdegradation Brazil nut extraction in Madre De Dios Peru World Dev 311873ndash1887

19 Fisher M (2004) Household welfare and forest dependence in southern Malawi En-viron Dev Econ 9135ndash154

20 Lopez-Feldman A Mora J Taylor JE (2007) Does natural resource extraction mitigatepoverty and inequality Evidence from rural Mexico and a Lacandona rainforestcommunity Environ Dev Econ 12251ndash269

21 Pattanayak S-K Sills E-O (2001) Do tropical forests provide natural insurance Themicroeconomics of non-timber forest product collection in the Brazilian AmazonLand Econ 77595ndash612

22 Angelsen A Wunder S (2003) Exploring the forestndashpoverty link Key concepts issuesand research implications Center for International Forestry Research Occasional Pa-per No70 (CIFOR Jakarta Indonesia)

23 Wunder S (2001) Poverty alleviation and tropical forestsmdashwhat scope for synergiesWorld Dev 291817ndash1833

24 Belcher B Schreckenberg K (2007) Commercialisation of non timber forest productsA reality check Dev Policy Rev 25355ndash377

25 Rawlings L Rubio G (2005) Evaluating the impact of conditional cash transfer pro-grams World Bank Res Obs 2029ndash55

26 Udry C (1996) Gender agricultural production and the theory of the household JPolit Econ 1041010ndash1046

27 Food and Agriculture Organization (1997) Womenrsquos Participation in National ForestProgrammes Formulation Execution and Revision of National Forest Programmes(Food and Agriculture Organization of the United Nations Rome)

28 Bellew R Raney L Subbarao K (1992) Educating girls Finance Dev Mar54ndash5629 Lybbert T Magnan N Aboudrare A (2010) Household and local forest impacts of

Moroccorsquos argan oil bonanza Environ Dev Econ 15439ndash46430 Direction de la Statistique (1999) Enquete Nationale Sur Les Niveaux de Vie des

Menages 199899 Premiers Resultats (Department du Haut Commissariat au PlanRabat Morocco)

31 Direction de la Statistique (2005) Annuaire statistique du Maroc (Department du HautCommissariat au Plan Rabat Morocco)

32 Rouse J (1974) Monitoring vegetation systems in the Great Plains with ERTS Pro-ceedings of the Third ERTS Symposium (NASA Washington DC) Vol 1 Section A pp309ndash317

33 Tucker C (1979) Red and photographic infrared linear combinations for monitoringvegetation Remote Sens Environ 8127ndash150

34 Gurgel H Ferreira N (2003) Annual and interannual variability of NDVI in Brazil and itsconnections with climate Int J Remote Sens 243595ndash3609

35 Lanfredi M Lasaponara R Simoniello T Cuomo V Macchiato M (2003) Multi-resolution spatial characterization of land degradation phenomena in southern Italyfrom 1985 to 1999 using NOAA-AVHRR NDVI data Geophys Res Lett 301069ndash1073

36 Nash M Wade T Heggem D Wickham J (2006) Does anthropogenic activities ornature dominate the shaping of the landscape in the Oregon pilot study area for1990ndash1999 Desertification in the Mediterranean Region A security issue Series CEnviron Security 3305ndash323

37 Bawa K et al (2002) Assessing biodiversity from space An example from the WesternGhats India Conserv Ecol 67ndash12

38 El Yousfi SM (1988) La Degradation Forestiere dans le Sud Marocain Example delrsquoArganeraie drsquoAdmine entre 1969 et 1986 MS thesis (Institut Agronomique et Vet-erinaire Hassan II Rabat Morocco)

39 Aziki S (2008) Degradation et Changements Ecologiques Dans La Reserve de Bio-sphere Arganeraie RARBAGTZ Rep

40 Lybbert TJ Barrett CB Narjisse H (2002) Market-based conservation and local bene-fits The case of argan oil in Morocco Ecol Econ 41125ndash144

41 Akerlof G (1970) The market for ldquolemonsrdquo Quality uncertainty and the marketmechanism Q J Econ 84488ndash500

42 Harold D (1967) Toward a theory of property rights Am Econ Rev 57347ndash35943 Lybbert TJ Barrett CB Narjisse H (2003) Does resource commercialization induce local

conservation A cautionary tale from southwest Morocco Soc Nat Resour 17413ndash43044 Anyamba A Tucker C (2005) Analysis of Sahelian vegetation dynamics using NOAA-

AVHRR NDVI data from 1981ndash2003 J Arid Environ 63596ndash61445 Carruthers R Anderson G (2008) Using classification and NDVI differencing methods

for monitoring sparse vegetation coverage A case study of saltcedar in Nevada USAInt J Remote Sens 293987ndash4011

46 Nash MS Chaloud DJ Kepner WG Sarri S (2009) Regional assessment of landscapeand land use change in the Mediterranean region Morocco case study (1981ndash2003)Environmental Change and Human Security Recognizing and Acting on Hazard Im-pacts NATO Science for Peace and Security Series C Environmental Security edsLiotta PH Mouat D Kepner WG Lancaster JM (Springer Berlin) pp 143ndash165

47 African Data Dissemination Service (2010) Early Warning System (US Geological Sur-vey) Available at httpearlywarningusgsgovfewsafricaindexphp Accessed July7 2011

sectsectThis nearest-neighbor matching controls for other geographically concentrated forestpressure that is common to both argan and nonargan forest (eg growth pressures onurban fringes agricultural conversion pressures near access to irrigation etc)

paraparaIf the argan tree was domesticated and nonargan forest was converted to argan forestin response to the argan boom this assumption would not hold Because this scenario isnot the case and argan reforestation was totally nonexistent in the past decade thisassumption is easily defensible

13968 | wwwpnasorgcgidoi101073pnas1106382108 Lybbert et al

Supporting InformationLybbert et al 101073pnas1106382108SI DiscussionBackground Argan tree and forest The argan tree [Argania spinosa(L) Skeels] is endemic to Morocco where it is second in cov-erage only to the cork oak tree and is ecologically indispensableIts deep roots are the most important stabilizing element in thearid ecosystem providing the final barrier against the en-croaching deserts (1 2) The tree is the foundation species ofthe broader ecoregion with diverse fauna of Palearctic andAfrotropical species (1 3) The argan forest (Fig S1) is sur-rounded by Acacia Juniperus and Tetraclinis (thuya) tree andshrub species (3) The tree resists domestication and is difficultto transplant or establish on any meaningful scale outside Mo-rocco (4)Argan forests are invaluable to the indigenousBerber tribeswho

rely on the tree for firewood and charcoal for heating and cookingfodder for livestock and oil for culinary cosmetic and medicinalpurposes Indeed nearly 90 of the rural economy in the regiondepends on argan-based agroforestry (5) which is governed byclear and well-established albeit complex tenure arrangements(Fig S2) Although some have argan trees on private land mosthouseholdsrsquo access argan fruit through usufruct rights in definedforest tracts called agdals that are collectively exploited outsidethe fruit harvest season Other portions of the collective forestcalled azrougs are collectively exploited all year by members ofthe assigned village (6)Despite its uniqueness and importance nearly one-half of the

argan forest disappeared during the 20th century Averagedensity of the remaining one-half dropped from 100 to less than30 trees per hectare Historical pressure from high-qualitycharcoal production (especially important during the WorldWars) and more recently conversion to export crops such astomatoes has been replaced by predominantly local threats Theprimary contemporary threat to the forest comes from thepersistent pressure associated with intensified livestock brows-ing and grazing which has effectively halted natural rege-neration in many parts of the forest and can steadily degrade thecanopy This livestock pressure is caused almost entirelyby goats and is particularly intense during dry years recoveryfrom these episodes can be painfully slow Although encroach-ing suburban and rural settlements continue to threaten theforest on a few edges of the forest goats are the primary threatthroughout the forestArgan boom Growing appreciation among chemists touristsentrepreneurs and cosmetic firms during the 1990s for theculinary and cosmetic properties of the oil extracted fromthe kernels inside argan fruit set the stage for dramatic changesin argan oil markets Entrepreneurs had already startedtapping higher-value tourist markets in 1999 and were lay-ing plans for expansion into Europe and North America Afew European cosmetic firms including YvesndashRoche andColgatendashPalmolive were experimenting with argan-basedmoisturizersAn even more potent early influence came from conservation

and development interests that sought to leverage high-valueargan markets to benefit locals empower women (who are pri-marily responsible for argan activities) and thereby promote

local conservation of the threatened forests (6)dagger Although manydomestic foreign and international development agencies havebeen involved in argan-related projects one project clearlystands out Le Projet Arganier funded jointly by the MoroccanAgence de Deacuteveloppement Social and the European UnionThis 7-y (2003ndash2010) euro12 million initiative aims to empower andimprove the lives of rural women in the argan region and pro-mote the protection and conservation of the forest by amongother things supporting the expansion of argan oil cooperativesfor women Largely because of its influence these cooperativeshave exploded from a handful involving a few hundred women in1999 to well over 100 cooperatives involving over 4000 womentoday This influx of external funding for argan oil cooperativesseems to have changed the characteristics and composition ofthese cooperativesAs a result of these private and public initiatives argan oil has

frequently attracted the mediarsquos gaze in the past decade It hasbeen featured in its own French documentary is showcased byjust about any tourist publication or production on Morocco andnow has dozens of websites dedicated to it Across this broadarray of media attention one strand is nearly always woven intothe argan story the wonderful winndashwin it offers consumers toprotect trees and help local women all while enjoying the manyvirtues of this liquid gold (8) Not surprisingly this compellingstory has fueled a veritable frenzy of argan activity with newargan oil producers distributors and cooperatives springing upat every turn to market the oil with references to the threatenedtree and the women involved in extracting the oilAlthough we focus these analyses on quantifiable impacts on

local households locals and nonlocals alike have responded inless quantifiable ways and these responses importantly mediatethe impact on rural households Booming argan prices have drawnrelatively rich local households into argan fruit collection Sim-ilarly the region is awash in private firms that pose as cooper-atives In bona fide womenrsquos cooperatives there are concernsthat men are steadily encroaching on what was at one timeconsidered the womenrsquos domain aloneImpacts on argan production and marketsTotal fruit production in theargan forest can vary wildly from year to year because of rainfallfluctuations but it is perfectly price inelastic in the short andmedium term An argan saplingmdashvery few of which typicallysurvive beyond a few yearsmdashcan take 20 y or more before pro-ducing fruit (9) Fruit collection is likely less inelastic than pro-duction but aggregate production and collection estimates donot exist making it difficult to assess whether fruit collectioncould expand in the near term Anecdotally locals seem to havebecome much more careful about how and how completely theycollect fruit in the last several years For example locals his-torically collected dried fruit by hand off the ground and alsocollected argan stones from the dung of their goats after they atefruit directly from the thorny tree canopy Because the fruit hasbecome more valuable locals are collecting much more fruit byhand which has likely made fruit collection more complete andexpanded slightly the amount of fruit available for oil extraction

Forest changes between 1957 and 1986 have been documented for a small section of theforest using aerial photos (7) We are aware of no attempts to assess trends for theentire argan forest using satellite imagery as we do here

daggerTwo different cooperative models emerged for pursuing these objectives The firstmodel was fueled by Zoubida Charrouf a professor of chemistry at the Mohammed VUniversity in Rabat who had spent years researching the chemical properties of arganoil In the mid-1990s Charrouf began organizing argan oil cooperatives for women inthe argan forest region The second effort was led by the German development agencyGTZ which also supported the development of argan oil cooperatives for women albeitof a different form A description of the differences between these initial argan oilcooperatives is in the work by Lybbert et al (6)

Lybbert et al wwwpnasorgcgicontentshort1106382108 1 of 5

This very modest fruit supply response however is swamped bythe recent explosion in argan oil demand and argan prices haveskyrocketed as a result Real argan fruit prices in rural marketshave roughly quadrupled since 1999 whereas oil prices in thesemarkets have tripledChanges in argan oil demandmdashprimarily spurred by efforts to

promote argan oilmdashhave driven significant differentiation in ar-gan markets Just over 10 y ago the bulk of argan oil was un-differentiated had questionable purity and was sold in reusedplastic bottles (often at roadside stands) The initiatives describedabove pioneered the path to high-value argan oil markets throughinvestments in oil quality testing to ensure purity mechanicalextraction packaging and labeling and distribution networksrequired to tap export markets Presently there are two broadargan oil markets one culinary and one cosmetic Culinary arganoil historically available only in or near the argan forest region isnow marketed across Morocco Europe the Middle East andNorth America Because this market spans dusty village souks andupscale restaurants in New York and Paris retail prices rangewidely from $18L to 20 times this amount making it the mostexpensive edible oil in the world The market for cosmetic arganoil has likewise exploded over the past decade Berbers have usedargan oil cosmetically for centuries (10) but introducing argan oilinto high-value cosmetic markets has required more than thistraditional knowledge including validation of its chemical prop-erties and mechanical extraction and processing technologies Oninternational markets pure argan oil is marketed as a naturalmoisturizer or added directly to a moisturizer or other cosmeticproduct A second and more research-intensive segment of thecosmetic argan market focuses on extracts from argan oil leavesfruit and seeds that are marketed as active ingredients in cos-metic treatments and it has generated a variety of patents inEurope and the United States (11) As with the culinary oilcosmetic firms are quick to leverage the winndashwin story of ruraldevelopment and conservationDagger

Improvements in packaging and labeling were the first step totapping high-value markets in the late 1990s Labeling is againemerging as a potentially important aspect of differentiation inargan markets this time in conjunction with certification Firstthere are currently several argan oil productsmdashboth culinary andcosmeticmdashthat are fair trade-certified by organizations such asAlterEco and Max Havelaar Many more products include labelclaims that locals benefit from the sale of the product without anyfair trade certification Next many have pushed to protect arganoil as a geographic indicator in Europe Last there is currently noclear certification to distinguish argan cooperatives from privatefirms which are indistinguishable to many localssect As a result theargan forest region is rife with cooperatives that function morelike a profit shop and small shops that pose as cooperatives but donot offer cooperative-type benefits to their memberspara

SI Materials and MethodsWe began studying local impacts of argan market changes in thelate 1990s and conducted a detailed survey of rural households inthe region in 1999 Eight years after this initial household surveyand after dramatic changes in local argan markets we returned tothese households for a second round of data collection (Fig S1)

The mesolevel analysis described in this paper seeks to scale upand complement these household dataThe infrastructure indexes used in the commune-level enroll-

ment analysis for Essaouira Province were constructed by factoranalysis The variables in the weak educational infrastructureindexmdashwith their respective scoring coefficientsmdashinclude thenumber of Koranic schools (minus023) primary schools (minus035)primary satellite schools (minus039) and middle schools (009) Thisindex has a mean of zero ranges from minus22 to 217 and increasesas educational infrastructure declines The variables in the weakother infrastructure index include indicators for accessibility bytaxi (minus055) and bus (minus032) and availability of electricity (minus009)and running water (minus008) This index has a mean of 047 rangesfrom minus177 to 089 and increases as other infrastructure (andaccessibility) declinesThe primary data source for this study was normalized differ-

ence vegetation index (NDVI) composite images generated by theNational Oceanic and Atmospheric Administration The NDVI iscalculated as [near infrared reflectance (NIR) minus visible red re-flectance of the sunlight (VRR)](NIR + VRR) (12 13) In thisformulation NIR distinguishes between vegetation and waterand VRR distinguishes between vegetation and man-madestructures As our source of this NDVI data we used advancedvery high resolution radiometer available from the USGeologicalSurvey (14) The images for the continent of Africa were con-verted to a grid defined to a common projection and clipped toa buffered (25 km) boundary of Morocco The NDVI datasetconsisted of 10-d composite NDVI data over a 28-y period (1981ndash2008) for 8 times 8 km pixels based on composite images generated bythe National Oceanic and Atmospheric AdministrationTo validate our use of NDVI as a measure of forest canopy

and by extension biodiversity in the ecoregion we comparedchanges in NDVI to rainfall patterns over time and establishedthat even small changes in rainfall can produce measurablechanges in NDVI This finding is consistent with other assess-ments that show that NDVI is strongly correlated with othermeasures of vegetative density even in arid and semiarid areas(15 16)Although NDVI is essential to our landscape-level analysis we

conducted a more rigorous validation exercise in which we usedrecent images from Google Earth to confirm that NDVI iscapturing meaningful dimensions of forest canopy in the arganregion Specifically we randomly selected NDVI pixels one-halfin the argan forest and one-half in adjacent nonargan forest Toimplicitly stratify by NDVI within each of these groups we sortedthe pixels by November 2009 NDVI chose a random startingpoint and selected every 20th pixel thereafter We then usedGoogle Earth to capture a sample of 18 1-km2 images from eachof these selected NDVI pixels Because our objective was to testthe correlation between our NDVI data and forest canopy wehandpicked these 1-km2 satellite images to ensure that they wererepresentative of the forest canopy in each NDVI pixel (eg weexcluded 1 km2 that contained villages and the surrounding rain-fed agricultural plots) We then used ArcGIS to identify tree andshrub canopies and to compute the total area of this canopy Inall we characterized the canopies of 194 1-km2 images in 12NDVI pixels Table S1 summarizes the percent canopy coveragein these images The correlation between NDVI and canopycoverage is high primarily because trees and shrubs althoughsparse in some locations are the dominant form of vegetationBased on an average correlation with NDVI of 094 and a cor-relation of 088 and 097 for argan and nonargan forest re-spectively we are confident that our NDVI data are indeedmeaningful measures of forest canopyAs described in the text the comparison of the NDVI trend for

the forest and canopy before the onset of the argan boom (1981ndash1998) and the same trend after the boom began (1999ndash2009) iscentral to our NDVI analysis Specifically we show difference in

DaggerCognis the leading firm in this segment has agreed to purchase its argan materials ata premium from an established cooperative

sectFor example 90 of the women that we surveyed in 2007 did not know the differencebetween a private firm and a cooperative

paraThese enterprises pose as womenrsquos cooperatives but are rarely managed by women andthey do not necessarily offer benefit sharing or literacy courses to their members Theyare not certified by any governing body although they might allude to the contrary andthey often pay guides to bring tourists to their faux cooperatives Many allegedly trafficdiluted argan oil to unsuspecting tourists

Lybbert et al wwwpnasorgcgicontentshort1106382108 2 of 5

the two estimated trend coefficients as Δbθz frac14 bθge1999z minusbθ

lt 1999z for

each pixel and use this estimated trend difference to assess theimpact of the argan boom on forest and canopy density Asa supplement to the text we display the distribution of thesetrend changes for pixels with argan canopy and pixels with othertree and shrub species in Fig S3 In the argan forest about asmany pixels experienced negative trend changes as positive

changes but relative to nearby forests of other species the argancanopy has apparently worsened since 1999The nearest-neighbor matching algorithm is implemented us-

ing STATArsquos nnmatch command where nonargan pixels aredrawn from within 1 or 2 pixels of the argan forest Becauseimperfect matches can bias estimated treatment effects we usethe bias adjustment proposed by Abadie and Imbens (17)

1 Msanda F El Aboudi A Peltier J (2005) Biodiversity and biogeography of Moroccanargan tree communities Cahiers Agricultures 14357ndash364

2 Morton J Voss G (1987) The argan tree (Argania sideroxylon Sapotaceae) a desertsource of edible oil Econ Bot 41221ndash233

3 World Wildlife Fund McGinley M (2007) Mediterranean acacia-argania drywoodlands and succulent thickets Mediterranean acacia-argania dry woodlands andsucculent thickets Encyclopedia of Earth ed Cleveland CJ (National Council forScience and the Environment Washington DC)

4 Nouaim R Mangin G Breuil M Chaussod R (2002) The argan tree (Argania spinosa) inMorocco Propagation by seeds cuttings and in-vitro techniques Agrofor Syst 5471ndash81

5 Benchekroun F (1990) Un Systeme Typique DrsquoAgroforesterie Au Maroc LrsquoArganeraieSeacuteminaire Maghreacutebin drsquoAgroforesterie (Jebel Oust Tunisia)

6 Lybbert TJ Barrett CB Narjisse H (2002) Market-based conservation and localbenefits The case of argan oil in Morocco Ecol Econ 41125ndash144

7 Jadaoui M (1998) Reacuteconciliation deacuteveloppementenvironnement agrave travers lrsquoapprochedu systegraveme Arganeraie dans le pays drsquoIda Ouzal (versants meacuteridionaux du haut Atlasoccidental) (Mohammed V University Rabat Morocco)

8 Larocca A (November 18 2007) Liquid gold inMoroccoNY Times Available at http travelnytimescom20071118travveltmagazine14get-sourcing-capshtml

9 Lybbert TJ Barrett CB Narjisse H (2003) Does resource commercialization induce localconservation A cautionary tale from southwest Morocco Soc Nat Resour 17413ndash430

10 MrsquoHirit O Benzyane M Benchekroun F El Yousfi SM Bendaanoun M (1998)LrsquoArganier Une espece fruitiere-forestiere a usages multiples (Report for MardagaSprimont Belgium)

11 Lybbert TJ (2007) Patent disclosure requirements and benefit sharing Acounterfactual case of Moroccorsquos argan oil Ecol Econ 6412ndash18

12 Rouse J (1974) Monitoring vegetation systems in the Great Plains with ERTSProceedings of the Third ERTS Symposium (NASA Washington DC) Vol 1 Section App 309ndash317

13 Tucker C (1979) Red and photographic infrared linear combinations for monitoringvegetation Remote Sens Environ 8127ndash150

14 African Data Dissemination Service (2010) Early Warning System (US Geological Survey)Available at httpearlywarningusgsgovfewsafricaindexphp Accessed July 7 2011

15 Minor T et al (1999) Evaluating change in rangeland condition using multitemporalAVHRR data and geographic information system analysis Environ Monit Assess 59211ndash223

16 Mauz K (2004) Correlation of Range Transect Data with Satellite Remote SensingVegetation Indices Range View Geospatial Tools for Natural Resource Management(University of Arizona) Available at httprangeviewarizonaedureportsRange_Transect_Dataindexphp

17 Abadie A Imbens G (2002) Simple and bias-corrected matching estimators foraverage treatment effects National Bureau of Economic Research Technical WorkingPaper No 283 (National Bureau of Economic Research Cambridge MA)

Lybbert et al wwwpnasorgcgicontentshort1106382108 3 of 5

Village commons Household usufruct Private LandMayJunJulAugSepOctNovDecJanFebMarApr

Note that the precise start and end of agdal season varies annually

Tem

pora

l Dim

ensi

on

Spatial Dimension

agda

l se

ason

Communal use (grazing wood collection etc)

Intensive communal use including fruit collection from

Azroug trees

Household use

Household fruit collection from Agdal trees

Houshold use including fruit collection from private trees

Fig S2 The spatial and temporal structure of usufruct rights to collect argan fruit

Argan forestCommune bordersEssouira ProvinceVillages in survey

Fig S1 Spatial distribution of the argan forest across communes in 1994 (source HCEFLCD) with the villages included in the 1999 and 2007 household surveysand the scope of the commune-level educational enrollment analysis (Essaouria Province) indicated The NDVI analysis of argan canopy density uses data fromthe entire argan forest region

Lybbert et al wwwpnasorgcgicontentshort1106382108 4 of 5

05

1015

20D

ensi

ty

-1 -05 0 05 1Change in NDVI Canopy Trend After Start of Market Boom

Argan CanopyOther Canopy

kernel = epanechnikov bandwidth = 00108

Includes pixels with p-values lt 015 amp mean NDVI gt 30Before-After Change in NDVI Canopy Trend

Fig S3 Kernel densities of the difference in the estimated NDVI canopy trend coefficients for pixels in the argan forest and other adjacent forests Thisdifference compares the trend before and after the start of the argan market boom (1999) We include only those pixels with precisely estimated trendcoefficients (P values lt 015) and some vegetative cover [mean NDVI (1981ndash2009) gt 30] which excludes pixels in the urban fringe or on the desert edge

Table S1 Summary statistics of NDVI validation of a random sample of NDVI pixels (implicitlystratified by NDVI) using 1-km2 satellite images taken from Google Earth

Canopy cover

Argan forest Nonargan forest Combined

Mean 11 103 107SD 125 18 15Maximum 67 59 67Correlation with NDVI 088 097 094N (1-km2 satellite images) 112 82 194

The images were taken between 2004 and 2009 The correlation with NDVI is based on the NDVI for the samedate that the image was taken

Lybbert et al wwwpnasorgcgicontentshort1106382108 5 of 5