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1 The Geographic Concentration of Economic Activity Across the Eastern United States, 1820-2010 by David A. Latzko Business and Economics Division Pennsylvania State University, York Campus 1031 Edgecomb Avenue York, PA 17403 phone: 717-771-4115 fax: 717-771-4062 e-mail: [email protected]

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The Geographic Concentration of

Economic Activity Across the Eastern

United States, 1820-2010

by

David A. Latzko

Business and Economics Division

Pennsylvania State University, York Campus

1031 Edgecomb Avenue

York, PA 17403

phone: 717-771-4115

fax: 717-771-4062

e-mail: [email protected]

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The Geographic Concentration of Economic Activity

Across the Eastern United States, 1820-2010

Abstract

The historical dynamics of the geographic distribution of economic activity across the eastern United

States between 1820 and 2010 are examined using the smallest feasible geographic entities, counties, as

units of analysis. The region first experienced increasing spatial concentration of population and

manufacturing, with inequality peaking early in the twentieth century. Population and manufacturing

have since become more dispersed. Agriculture showed the opposite pattern: initial dispersion followed

by increasing concentration. Initially, counties with a high manufacturing density also had a high

agricultural density. Eventually, agricultural production moved to outlying areas while manufacturing

remained concentrated near where it originated.

keywords: spatial distribution, geographic distribution, regional economic activity, regional

economic development, regional economic history, location of economic activity

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The Geographic Concentration of Economic Activity Across the Eastern United

States, 1820-2010

A striking characteristic of the modern economy is the very uneven distribution of economic

activity across space. This is the result of several sometimes-contradictory influences. The neoclassical

growth model predicts convergence: the economies of low-income regions will grow faster than the

economies of high-income regions so that the income levels of poor economies will tend to approach

those of rich economies. Diminishing returns to capital means that poorer regions will have a higher

marginal product of capital and so a higher growth rate than rich regions, enabling the poor regions to

catch up in the long run. Convergence implies a reduction over time of differences in the distribution of

economic activity across geographic regions.

Evidence of convergence has been found for many national and continental areas, including U.S.

regions and states,1 European regions,

2 Japanese prefectures,

3 Canadian provinces,

4 U.S. counties,

5 and

counties of the Great Plains states.6 Niemi identified a divergence between the industrial structure of the

South and the rest of the United States during the second half of the nineteenth century, but noted a steady

convergence of both regional and state manufacturing structures during the period 1860-1970.7

Students of economic geography and urbanization emphasize agglomeration economies, the

benefits producers obtain when located near each other. These benefits, a combination of scale

economies and network externalities, can come from the supply side of the market (information

spillovers, competing suppliers, thicker labor markets with many buyers and sellers, and so on) as well as

from the demand side, for example, the home market effect. Agglomeration economies push the

geographical concentration of economic activity. Agglomeration diseconomies - congestion, higher input

prices, and product price competition - encourage the dispersal of economic activity.8

Ellison and Glaeser find that most American industries are geographically concentrated, and

Rappaport and Sachs observe that the concentration of U.S. industry on ocean and Great Lakes coasts

increased over the twentieth century.9 Wheaton and Shishido, using cross-sectional data for 38 counties,

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find that urban concentration initially rises with per capita income but eventually spatial decentralization

sets in as economic development proceeds.10

Ades and Glaeser determine that the urban concentration of

population is related to political and trade factors.11

In France, extractive, traditional, and high tech

industries are highly localized, and Devereux, Griffith, and Simpson find a high degree of geographic

concentration in some U.K. industries in 1992.12

Regional industrial specialization in China increased

between 1988 and 2001, and its center of population has gradually moved towards the southeast over the

last two millennia.13

In a seminal paper, Williamson hypothesized that as a country develops from low-income levels,

regional income inequality increases and economic activity becomes more spatially concentrated. As

development proceeds, diminishing returns to capital and agglomeration diseconomies occur in the initial

growth region, leading to economic development elsewhere and a decline in regional income inequality.

‘The expected result is that a statistic describing regional inequality will trace out an inverted “U” over

the national growth path…’14

The broad narrative of industrial development in the United States has been traced by Klein,

Licht, Meyer, and Niemi.15

Statistical evidence on the changing spatial distribution of economic activity

was provided by Krugman and Kim, who analyzed manufacturing specialization across U.S. states and

the nine census divisions.16

Regional manufacturing specialization, measured by employment, declined

slightly between 1860 and 1890, rose substantially in the early twentieth century, to peak in the 1910’s,

flattened out during the interwar years, and fell considerably thereafter. Easterlin found a decline in the

concentration of manufacturing production among U.S. states between 1869 and 1947, and Dumais,

Ellison, and Glaeser determined that there was a slight decline in industry agglomeration levels across

U.S. states between 1972 and 1992.17

In Europe population has concentrated spatially since the

eighteenth century.18

Ireland and Portugal saw little change between 1985 and 1998 in agglomeration

levels but there was extensive geographic mobility of industries.19

The geographic concentration of

aggregate employment across Western Europe did not change over the 1975-2000 period although

manufacturing became less concentrated relative to physical space.20

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To sum up, economic activity is very unevenly distributed across geographic space. The

theoretical and empirical literature indicates that the degree of this spatial inequality is not constant over

time. Here I examine the historical dynamics of agglomeration and economic concentration across the

United States over the very long run. Previous studies of this topic have used census regions or states as

the units of analysis. But, economic activity is not at all evenly distributed across such large geographic

units.21

Therefore, I use the smallest possible geographic entities, counties, as units of analysis to provide

a more precise empirical examination of the location of economic activity over time.

Several studies of regional economic growth, such as the Higgins, Levy, and Young and Austin

and Schmidt papers cited above, examine county-level income data, but for time periods (1970-1998 and

1969-1994 respectively) too short to reveal the long-run distribution of economic activity across county-

sized units.22

The contribution of this paper lies in its consideration of a significant geographical area --

the eastern United States -- through an extended period of time -- 1820-2010.

Data and methods

Williamson’s inverted-U hypothesis posits three stages of regional development: increasing,

stable, and decreasing regional inequality. Data, then, are needed over a long period of time to test the

Williamson hypothesis. Counties are the logical unit of analysis as they are the smallest geographic

entities, together covering the entire eastern United States, for which a long time series of economic data

can be constructed. Beginning in 1820, the decennial U.S. censuses contain tabulations by county of

various economic variables.23

Later, periodic economic censuses provide county-level data.

County-level data are also appealing for the theoretical reason suggested by Beeson, DeJong, and

Troesken: ‘[C]ounty borders are attractive because they better reflect the limits of local economies than

do the borders of states, regions, or nations, which are aggregates of local economies; or cities, whose

political boundaries often exclude a portion of the local economy…’24

City-level data, by ignoring

suburban and rural locations, fail to span the entire geographic space.

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Inequality in the distribution of economic activity in the eastern United States is measured by the

Gini coefficient, a measure of statistical dispersion in a population that has been used to measure

inequality in plant size, to quantify carbon use by bacterial soil communities, and to examine the equality

of student participation in classroom discussions.25

Most often used to summarize income inequality, the

Gini coefficient has been utilized by Amiti and Krugman to measure the geographic concentration of

industry.26

If the data are ordered by increasing size, the Gini coefficient is given by

(1) (n

i=1(2i – n – 1)xi)/n2

,

where x is an observed value, n is the number of values observed, i is the rank of values in ascending

order, and is the mean value of x. The Gini coefficient ranges from a minimum value of zero for perfect

equality, when all units have the same value of x, to a theoretical maximum of one when a single unit has

all of x and the other units have nothing. Higher Gini coefficients indicate a more unequal distribution.

This paper maps and analyses data using the county boundaries extant at the time of each

decennial census, taken from Thorndale and Dollarhide’s invaluable Map Guide to the U.S. Federal

Censuses.27

Because county boundaries have changed units of analysis are not consistent over time but,

although this inconsistency may bias the Gini coefficient downwards, it has little impact on observed

inequality. For example, when county-level census figures first become available for Florida and

Wisconsin, between 1830 and 1840 the number of counties in this analysis increased from 914 to 1,155.

Dropping these two states from the calculation reduces the Gini coefficient for 1840 from 0.64 to 0.63 for

population density; the Gini coefficient for agricultural density falls from 0.45 to 0.44 and that for

manufacturing density falls from 0.92 to 0.91.

This paper considers the counties of all states east of the Mississippi River (Alabama,

Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland,

Massachusetts, Michigan, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio,

Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia, West Virginia, and

Wisconsin) and the District of Columbia. The number of counties in the analysis ranges from 731 to

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1638. Three measures of economic activity are constructed for each county: agricultural density,

manufacturing density, and population density.28

All densities are per square mile of county area.

In the long run, increases in population are strongly correlated with economic development, both

as indicators and as consequences.29

Rappaport and Sachs argue that population density captures

underlying variations in local productivity and quality of life. Consider an area with a set of attributes

such as access to navigable water, temperate weather, and rule of law that increase the productivity of

resident firms. The high productivity of firms increases the marginal products of both labor and capital,

inducing an inflow of each. In the long run, high productivity implies high population density. Also,

consider an area with a set of attributes such as waterfront activities, pleasant weather, and low crime that

increase the quality of life of local residents. The high quality of life induces an inflow of labor and, since

it is complementary, capital. In the long run, high quality of life implies high population density.

Consistent with the idea that people vote with their feet, the intuition is that ‘population density reveals

individuals’ preferences over local areas by aggregating the indirect contribution to utility via

productivity-driven higher wages with the direct contribution to utility via high quality of life.’ 30

Glaeser also argues that a high population density is associated with a higher standard of living.31

People acquire skills by interacting with one another, and a dense population increases these interactions.

So, a high population density results in a population with lots of human capital which then attracts more

people. However, Acemoglu, Johnson, and Robinson find that population density is not a good proxy for

economic prosperity in the recent data.32

No single indicator of agricultural or manufacturing activity is available for over the whole study

period. Tables 1 and 2 list the metrics used to compute county agricultural and manufacturing densities

(most often the value of farm products and the value of products in manufacturing) and the sources of the

data. There are a few years for which the agricultural or manufacturing measures utilized overlap. In

1950, the correlation between the value of all crops and the value of farm products sold is 0.73. The

correlation at the county level between the number of persons engaged in manufacturing in 1840 and the

total capital invested in manufacturing is 0.92, and the correlation in 1850 between the capital invested in

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manufacturing and the value of products in manufacturing in a county is 0.95. These correlations give

confidence to the notion that the results obtained below are not due to the choice of variables. No

agricultural or manufacturing data are available for 1830; no manufacturing data are available for 1910.

Evolution of the geographic concentration/dispersion of economic activity

The Gini coefficients for the three measures of economic activity are listed in Table 3.

Population density, a proxy for local productivity and quality of life, follows an approximate inverted-U

pattern. As Figure 1 indicates, population became increasingly concentrated through the nineteenth and

into the twentieth century with the Gini coefficient reaching a maximum in 1950. Thereafter, population

slowly became more dispersed across the eastern United States. Six major counties/cities in the region,

Manhattan, Philadelphia, Baltimore, Washington, DC, Boston, and Brooklyn, experienced absolute

declines in population density of over 2,000 persons per square mile between 1950 and 2010. The

Northern Virginia counties of Arlington and Fairfax, the New York City boroughs of Queens and Staten

Island along with Nassau County (New York), Pinellas County (Florida), and DuPage County (Illinois)

have seen the largest absolute gains in population density since 1950, with each gaining at least 2,000

persons per square mile. In percentage terms, several Florida counties including Collier and Charlotte

have seen the largest growth in population density since 1920. Still, population is far more unequally

distributed across the eastern United States today than anytime before World War I.

Figures 2 plots the Gini coefficients for manufacturing density. Manufacturing, consistently the

most concentrated of the three measures of economic activity, traces out a near inverted-U shape.

Manufacturing concentrated rapidly between 1820 and 1850, then slowed to 1890 when manufacturing

inequality peaked. In 1890, counties containing Manhattan, Chicago, Philadelphia, Brooklyn, Pittsburgh,

Boston, and Cincinnati accounted for 37 percent of manufacturing production the eastern United States.

By 2010, just 6 percent of manufacturing output was generated in these counties.

The Gini coefficient for manufacturing density was essentially flat between 1850 and 1950 at an

extremely high level. After World War II, manufacturing production dispersed across the eastern half of

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the country, with this dispersion accelerating since the late 1980’s. The seven leading manufacturing

counties in 2010, Cook County (Illinois), Wayne County (Michigan), Marion County (Indiana), Fairfield

County (Connecticut), Middlesex County (Massachusetts), Hamilton County (Ohio), and Oakland County

(Michigan) are mostly suburban and accounted for around 10 percent of the manufacturing value added in

the eastern half of the United States. Much manufacturing production has moved from the major cities to

their suburbs yet manufacturing still remains highly concentrated.

Figure 3 shows that agriculture, the least unequally distributed of the three variables over the

entire study period, reveals a pattern of slowly decreasing inequality to 1910 when agricultural production

was widely dispersed across the eastern states, followed by a more rapid increase in spatial concentration.

This pattern is consistent with estimates of productivity growth in agriculture. Total factor productivity

grew about 0.80 percent per year between 1850 and 1900, with the shift of farm output into new areas

accounting for a substantial part of the increase in productivity.33

As agricultural production grew more

concentrated in the twentieth century, marginal lands were abandoned and total factor productivity growth

accelerated, especially after World War II; productivity growth in agriculture averaged 1.9 percent a year

between 1948 and 1999.34

Consequently, agricultural production is more concentrated today than in

1820. In 1910, the top 10 agricultural producing counties accounted for nearly 4 percent of production in

the eastern United States; the top 10 in 2010 grew about 8 percent of the farm output in the region.

In the following analysis a county is defined as agriculture-dense if its agricultural density is

more than two standard deviations above the mean for all counties in the eastern United States. A county

is manufacturing-dense if its manufacturing density is greater than two standard deviations above the

mean for all counties. The maps in Figures 4 through 11 highlight the agriculture-dense and

manufacturing-dense counties in 1820, 1890, 1950, and 2010.35

The appendix lists these counties for

each of those four years.

In 1820, just three counties were manufacturing-dense: New York (Manhattan, New York),

Suffolk (Boston, Massachusetts), and Philadelphia (Pennsylvania). Agricultural production

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was scattered about the eastern United States, with pockets of concentration in the tidewater region of

Virginia, the area around Washington, DC, upstate New York, central Georgia, and northern Kentucky.

The densest agricultural county in 1820 was Philadelphia.

Figures 6 and 7 highlight the striking fact that economic activity in 1890, both agricultural and

manufacturing, was concentrated in the northeastern urban corridor. Four of the manufacturing-dense

counties, Baltimore City, Philadelphia, Kings, New York, and Hudson, New Jersey, were also agriculture

dense. Manhattan and Boston were the other two manufacturing-dense counties. Agricultural production

in 1890 was concentrated in southeastern Pennsylvania, northern New Jersey, southern and western New

York, and outside of Boston. Even in areas outside of the northeast, agricultural production was

concentrated around major industrial centers like Pittsburgh, Cleveland, Cincinnati, Chicago, New

Orleans, and Louisville. ‘A pattern of regional specialization existed with land-intensive, higher-

transport-cost products being produced closer to the major northeastern markets, while land-intensive,

lower-transport-cost-products were produced at a distance.’36

The same six counties that were manufacturing-dense in 1890 remained manufacturing dense in

1950, with Hudson County,New Jersey also agriculture dense. Figure 8 demonstrates that agricultural

production in the eastern United States had moved west. Large areas of central Indiana, northern and

central Illinois, and southeastern Wisconsin were agriculture dense. Agricultural output stayed high in the

Philadelphia/New York corridor. Pockets of agricultural density appeared in North Carolina, the

Delmarva Peninsula, and Mississippi.

Figures 10 and 11 depict the diffusion of economic activity, especially manufacturing, across the

eastern United States in 2010. 32 counties now had manufacturing densities more than two standard

deviations above the mean. The old manufacturing centers of Baltimore, Philadelphia, New York, and

Boston remained among the manufacturing dense counties, but manufacturing production also spread to

the suburban counties of these cities. Cleveland, Detroit, Milwaukee, Cincinnati, and Chicago and its

suburbs now appeared on the list of manufacturing dense areas as manufacturing production also moved

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to the Mid West. Manufacturing production also spread south, with manufacturing dense counties in

Virginia, North Carolina, and Louisiana.

Agricultural production moved south with areas of concentration in Virginia, North Carolina,

Georgia, Florida, and Alabama. New Jersey was no longer agriculturally-dense but neighboring areas of

southeastern Pennsylvania were. No counties were simultaneously manufacturing and agriculture-dense

in 2010.

Although areas of agricultural and manufacturing concentration have shifted south and west in

the eastern United States since 1820, a quick glance at Figures 4 through 11 reveals that a few counties

have remained agriculture or manufacturing dense for nearly 200 years. All those counties identified as

manufacturing-dense in 1820 were still among the manufacturing-dense counties in 2010. And, the two

densest agricultural counties in 2010, Woodford and Fayette in Kentucky, were agriculture-dense in 1820.

Indeed, there is tremendous stability in the rank- ordering of counties by agricultural, manufacturing, and

population densities between 1820 and 2010.

I sort counties by agricultural, manufacturing, and population densities for each year and

calculate the Spearman rank order correlation coefficient, which measures the strength of the association

between a county’s rank-ordering in year x on that metric and its rank-order in year y. These correlations

are listed in Table 4. While there is little correlation between a county’s agricultural density rank in 1820

and its rank in 2010, there are strong correlations for manufacturing, 0.39, and population, 0.49, ranking

between those dates. The correlations between rank in the past and rank in 2010 are stronger for all three

density metrics when comparing rank in 2010 to rank in 1890 and rank in 1950. There is a strong

relationship between current and past economic activity: the most economically-dense counties in 2010

tend to be the counties that were the most economically-dense in 1950 and in 1890 and in 1820.

Correlation between agricultural and manufacturing density

In Krugman’s two-region model of the geographic concentration of manufacturing, mass

production and lower transport costs produce an increasingly concentrated manufacturing core and an

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agricultural periphery.37

As transport costs to and from rural areas fall, manufacturers can afford to

concentrate in cities to take advantage of scale economies, intensifying the trend towards the

concentration of manufacturing in urban areas and agriculture in rural areas.38

According to Krugman’s

model, then, counties with a high manufacturing density ought to have a low agricultural density and

counties with a high agricultural density ought to have a low manufacturing density.

On the other hand, Meyer argues that agriculture and manufacturing were complements during

the initial phase of American industrial development. Eastern agriculture thrived before the Civil War as

rising farm productivity produced surplus labor for the factories and provided abundant farm products for

the growing urban population. Farms on poor soil and distant from urban markets declined while farmers

on good soil with good access to urban markets thrived.39

The implication of Meyer’s hypothesis is that

there ought to be a positive correlation between agriculture and manufacturing densities during the early

phase of industrial development.

I calculate the correlation between a county’s agricultural density and its manufacturing density

for each year. Figure 12 plots these agriculture/manufacturing density correlation coefficients.

Consistent with Meyer’s argument, there was a positive correlation between agricultural density and

manufacturing density until 1920. Since then, there has been a very weak negative or positive correlation

between the two variables. In other words, in the early stages of development, counties with a dense

manufacturing sector also had a dense agricultural sector. Most of the economic activity in the region,

both manufacturing and agricultural, took place in a handful of counties. In 1850, nine counties

comprising just 0.5 percent of the land area of the eastern United States -- New York County,

Philadelphia and Allegheny Counties (Pennsylvania), Baltimore, Essex, Middlesex, Suffolk and

Worcester Counties (Massachusetts), and Hamilton County (Ohio) -- produced 21 percent of its combined

agricultural and manufacturing output (2 percent of agricultural output and 33 percent of manufacturing

output) and contained 9 percent of the region’s population.

Technological advances in the transportation and processing of agricultural output weakened the

positive link between manufacturing and agricultural density over the second half of the nineteenth

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century as agricultural production became more dispersed across the eastern half of the United States

while manufacturing grew increasingly concentrated. Railroad construction was most rapid between

1850 and 1875. Rail transportation was available during all seasons, which was not true of wagon or

water transportation. Manufacturers and farmers had year-round access to market. Another advantage of

railroads for farmers was their time-saving. Perishable products such as milk, fruit, and vegetables could

be marketed greater distances. The first shipment of meat in refrigerated cars was in 1869, and a

refrigerated car for transporting fruit was introduced in 1887. Southern and Pacific coast produce became

available in Pennsylvania markets, for example, beginning about 1885. 40

Commercial canning began

about 1890 and the quick freezing of vegetables started in 1931. These two developments enabled

agricultural products to be transported and stored throughout the year. The advent of good roads and

motor vehicles in the early twentieth century permitted farmers to bring their products to market

themselves. Over the nineteenth and into the twentieth century, these improvements in food processing

and distribution caused agricultural production to disperse to outlying regions while manufacturing

remained concentrated near those areas where it initially sprang up in order to continue to benefit from

agglomeration economies.

The spatial relationship between manufacturing and agricultural production completely collapsed

during the first decades of the twentieth century. It was around this same time that the current trends

towards a dispersion of manufacturing production and an increasing concentration of agricultural

production across the region began. As new methods of food processing, distribution, and storage were

developed, marginal lands were taken out of cultivation, leaving agricultural production increasingly

concentrated on the most productive farmland. In Pennsylvania, for example, the land in farms fell from

19,371,015 acres in 1900 to 14,112,841 acres in 1950, close to the acreage a century earlier.41

‘The

primary cause of this shrinkage was the abandonment of rough or infertile land.’42

Consistent with

Nerlove and Sadka’s model of a dual economy, as the relative cost of transporting agricultural goods has

fallen, it became economically feasible to cultivate rural land.43

And so, agricultural production in the

eastern United States moved further away from the northeastern urban corridor.

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Conclusions

As the eastern half of the United States developed economically, it first experienced increasing

inequalities in the spatial distributions of population and manufacturing. Both forms of economic activity

concentrated around New York City, Philadelphia, Boston, and Baltimore. Spatial differentiation reached

a peak in the early post-World War II era. Since then, population and manufacturing production have

become more dispersed across the eastern United States. These patterns are consistent with Williamson’s

inverted-U hypothesis. Observed national development patterns replicate themselves over the long run

across smaller geographic areas, even with the smallest feasible spatial units of analysis. Aggregate

manufacturing concentration follows the same historical pattern of concentration-then-dispersal as the

micro industry-based data reported by Krugman and Kim and the rank-ordering of county manufacturing

density is persistent.44

The leading manufacturing counties in 2010 were the leaders over a century ago.

Agriculture, likely because the expansion of railroads and the introduction of refrigerated cars,

the building of good roads and the development of motor transportation, and the rise of commercial

canning, showed the opposite pattern: initial dispersion followed by increasing concentration. If these

trends continue, manufacturing production will become even more dispersed across the region.

Manufacturing leadership, having moved over the post-war era from the large cities to their suburbs, may

move to the exurbs and population will follow. As exurban land is converted to industrial and residential

use, agricultural production will become further concentrated in the region.

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APPENDIX

Agriculture and Manufacturing Dense Counties

1820 Agriculture

Philadelphia, PA Calvert, MD Jones, GA Jasper, GA

Mathews, VA Windham, VT St. Lawrence, NY Prince George’s, MD

Clark, KY Elizabeth City, VA Norfolk, MA Northumberland, VA

Schoharie, NY Putnam, GA Fayette, KY Prince William, VA

Tompkins, NY Charleston, SC Mason, KY Talbot, MD

Stafford, VA Cecil, MD Gloucester, VA Woodford, KY

1820 Manufacturing

New York, NY

Suffolk, MA

Philadelphia, PA

1890 Agriculture

St. Lawrence, NY New Castle, DE Cuyahoga, OH Campbell, KY

Kings, NY Assumption, LA Baltimore City, MD Wayne, NY

Hudson, NJ Milwaukee, WI Monmouth, NJ Kane, IL

Delaware, PA Hamilton, OH Essex, NJ Fayette, KY

Montgomery, PA Onondaga, NY West Baton Rouge, LA Cayuga, NY

Philadelphia, PA Westchester, NY Genesee, NY St. James, LA

Bucks, PA Middlesex, MA Mason, KY Orleans, NY

Queens, NY Orange, NY Richmond, NY Hunterdon, NJ

Lancaster, PA Camden, NJ Baltimore, MD Erie, OH

Monroe, NY Lehigh, PA DuPage, IL Ascension, LA

Schoharie, NY Ontario, NY Niagara, NY Essex, MA

Chester, PA Union, NJ Yates, NY Seneca, NY

Mercer, NJ Hartford, CT Northampton, PA Woodford, KY

Gloucester, NJ Allegheny, PA Montgomery, OH McHenry, IL

1890 Manufacturing

New York, NY

Baltimore City, MD

Philadelphia, PA

Suffolk, MA

Kings, NY

Hudson, NJ

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1950 Agriculture

Hudson, NJ Bourbon, KY Nassau, NY Champaign, IL

St. Lawrence, NY Boone, IL Ogle, IL Sangamon, IL

Sussex, DE Mercer, NJ Nash, NC Calumet, WI

Hartford, CT Lake, TN Woodford, KY Douglas, IL

DeKalb, IL Hunterdon, NJ Carroll, IL Green, WI

Kane, IL Whiteside, IL McLean, IL Dodge, WI

Monmouth, NJ Sunflower, MS Pitt, NC Caroline, MD

Schoharie, NY Suffolk, NY Wicomico, MD Kenosha, WI

Wilson, NC Walworth, WI McHenry, IL Carroll, IN

Fayette, KY Stephenson, IL Howard, IN Macon, IL

Gloucester, NJ Bureau, IL Rush, IN Clark, KY

Cumberland, NJ Tipton, IN Bergen, NJ Fond Du Lac, WI

Greene, NC Fulton, OH Benton, IN Boone, IN

Henry, IL Piatt, IL Coahoma, MS LaSalle, IL

Warren, IL Middlesex, NJ Seminole, FL DeWitt, IL

Union, NJ Racine, WI Northampton, VA Dane, WI

Kendall, IL Clinton, IN Stark, IL Jessamine, KY

Salem, NJ Logan, IL Lee, IL Moultrie, IL

1950 Manufacturing

New York, NY

Hudson, NJ

Kings, NY

Philadelphia, PA

Suffolk, MA

Baltimore City, MD

2010 Agriculture

Woodford, KY Ottawa, MI Wilkes, NC Adams, IN

Fayette, KY Union, NC Gordon, GA Carroll, IL

Duplin, NC McLean, KY Calumet, WI Jay, IN

Sampson, NC Banks, GA Madison, GA Hillsborough, FL

Franklin, GA Bourbon, KY Mitchell, GA Colquitt, GA

Mercer, OH Rockingham, VA Jackson, GA White, IN

Lancaster, PA St. Mary’s, MD Hendry, FL Gilmer, GA

Sussex, DE Lenoir, NC Brown, WI Huron, MI

Wayne, NC Caroline, MD Newton, IN Lagrange, IN

Hart, GA Kewaunee, WI Hall, GA Wayne, OH

Darke, OH Cullman, AL Allegan, MI Elkhart, IN

Greene, NC Hickman, KY DeKalb, IL Graves, KY

Chester, PA DeKalb, AL Page, VA Stephenson, IL

Jessamine, KY Wicomico, MD Dubois, IN

Lebanon, PA Jasper, IN Palm Beach, FL

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2010 Manufacturing

New York, NY Philadelphia, PA Queens, NY Fairfield, CT

Union, NJ Milwaukee, WI Bergen, NJ Jefferson, KY

Rockland, NY Henrico, VA DuPage, IL Essex, MA

Essex, NJ Kings, NY Delaware, PA St. Charles, LA

Warwick, VA Baltimore City, MD Cuyahoga, OH St. John the Baptist, LA

Suffolk, MA Hamilton, OH Forsyth, NC Durham, NC

Marion, IN Hudson, NJ Montgomery, PA Middlesex, NJ

Cook, IL Wayne, MI Lake, IL Vanderburgh, IN

FOOTNOTES

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Martin, Convergence, Journal of Political Economy 100 (1992) 223-251.

2. Barro and Sala-i-Martin, Convergence across states and regions.

3. R. J. Barro and X. Sala-i-Martin, Regional growth and migration, Journal of the Japanese and

International Economies 6 (1992) 312-346.

4. S. Coulombe and F. C. Lee, Convergence across Canadian provinces, 1961 to 1991, Canadian Journal

of Economics 28 (1995) 886-898.

5. M. J. Higgins, D. Levy, and A. T. Young, Growth and convergence across the United States: evidence

from county-level data, Review of Economics and Statistics 88 (2006) 671-681.

6. J. S. Austin and J. R. Schmidt, Convergence amid divergence in a region, Growth and Change 29

(1998) 67-88.

7. A. W. Niemi, Structural shifts in Southern manufacturing, 1849-1899, Business History Review 45

(1971) 79-84; A. W. Niemi, State and Regional Patterns in American Manufacturing 1860-1900,

Westport, CT, 1974.

8. G. S. Goldstein and T. J. Gronberg, Economies of scope and economies of agglomeration, Journal of

Urban Economics 16 (1984) 91-104; R. W. Helsley and W. C. Strange, Matching and agglomeration

economies in a system of cities, Regional Science and Urban Economics 20 (1990) 189-212; S. S.

Rosenthal and W. C. Strange, The determinants of agglomeration, Journal of Urban Economics 50 (2001)

191-229.

9. G. Ellison and E. L. Glaeser, Geographic concentration in U.S. manufacturing industries: a dartboard

approach, Journal of Political Economy 105 (1997) 889-927; J. Rappaport and J. D. Sachs, The United

States as a coastal nation, Journal of Economic Growth 8 (2003) 5-46.

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10. W. C. Wheaton and H. Shishido, Urban concentration, agglomeration economies, and the level of

economic development, Economic Development and Cultural Change 30 (1981) 17-30.

11. A. F. Ades and E. L. Glaeser, Trade and circuses: explaining urban giants, Quarterly Journal of

Economics 110 (1995) 195-227.

12. F. Maurel and B. Sedillot, A measure of the geographic concentration in French manufacturing

industries, Regional Science and Urban Economics 29 (1999) 575-604; M. P. Devereux, R. Griffith, and

H. Simpson, The geographic distribution of production activity in the UK, Regional Science and Urban

Economics 34 (2004) 533-564.

13. Z. Liang and L. Xu, Regional specialization and dynamic pattern of comparative advantage: evidence

from China’s industries 1988-2001, Review of Urban and Regional Development Studies 16 (2004) 231-

244; J. Wu, R. Mohamed, and Z. Wang, Agent-based simulation of the spatial evolution of the historical

population in China, Journal of Historical Geography 37 (2011) 12-21.

14. J. G. Williamson, Regional inequality and the process of national development: a description of the

patterns, Economic Development and Cultural Change 13 (1965) 9-10.

15. M. Klein, The Genesis of Industrial America, 1870-1920, Cambridge,2007; W. Licht, Industrializing

America: The Nineteenth Century, Baltimore, 1995; D. R. Meyer, Emergence of the American

manufacturing belt: an interpretation, Journal of Historical Geography 9 (1983) 145-174; A. Niemi,

Structural and labor productivity patterns in United States manufacturing, 1849-1899, Business History

Review 46 (1972) 67-84.

16. P. Krugman, Geography and Trade, Cambridge, MA, 1991; S. Kim, Expansion of markets and the

geographic distribution of economic activities: the trends in U.S. regional manufacturing structure, 1860-

1987, Quarterly Journal of Economics 110 (1995) 881-908.

17. R. A. Easterlin, Redistribution of manufacturing, in: S. Kuznets, A. Ratner Miller, and R. A. Easterlin

(Eds.), Population Redistribution and Economic Growth: United States, 1870-1950, volume II, Analyses

of Economic Change, Philadelphia, 1960, 103-139; G. Dumais, G. Ellison, and E. L. Glaeser, Geographic

concentration as a dynamic process, Review of Economics and Statistics 84 (2002) 193-204.

18. M. I. Ayuda, F. Collantes, and V. Pinilla, From locational fundamentals to increasing returns: the

spatial concentration of population in Spain, 1787-2000, Working Paper 2005-05, Faculty of Economics

and Business, University of Zaragoza, 2005.

19. S. Barrios, Salvador, L. Bertinelli, E. Strobl, and A. Teixeira, The dynamics of agglomeration:

evidence from Ireland and Portugal, Journal of Urban Economics 57 (2005) 170-188.

20. M. Brulhart and R. Traeger, An account of geographic concentration patterns in Europe, Regional

Science and Urban Economics 35 (2005) 597-624.

21. B. Trendle, Sources of regional income inequality: an examination of small regions in Queensland,

Review of Urban and Regional Development Studies 17(2005) 35-50.

22. Higgins, Levy, and Young, Growth and convergence across the United States; and Austin and

Schmidt, Convergence amid divergence in a region.

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23. The 1810 Census also collected data on manufacturing production. However, for the Census of 1810,

neither Congress nor the Secretary of the Treasury provided the U.S. Marshals conducting the census with

specific instructions as to what information about manufacturing establishments to collect. As a result,

the quality and quantity of the information collected varied greatly from numerator to numerator, making

the 1810 data not reliable enough for cross-county comparisons.

24. P. E. Beeson, D. N. DeJong, and W. Troesken, Population growth in U.S. counties, 1840-1990,

Regional Science and Urban Economics 31(2001) 671.

25. C. Damgaard and J. Weiner, Describing inequality in plant size or fecundity, Ecology 81(2000) 1139-

1142; J. Weiner and O. L. Solbrig, The meaning and measurement of size hierarchies in plant

populations, Oecologia 61(1984) 334-336; B. D. Harch, R. L. Correll, W. Meech, C. A. Kirkby, and C. E.

Pankhurst, Using the Gini coefficient with BIOLOG substitute utilisation data to provide an alternative

quantitative measure for comparing bacterial soil communities, Journal of Microbiological Methods

30(1997) 91-101; M. Warschauer, Comparing face-to-face and electronic discussion in the second

language classroom, Calico Journal 13(1996) 7-26.

26. M. Amiti, New trade theories and industrial location in the EU: a survey of evidence, Oxford Review

of Economic Policy 14(1998) 45-53; P. Krugman, Geography and Trade.

27. W. Thorndale and W. Dollarhide, Map Guide to the U.S. Federal Censuses, 1790-1920, Baltimore,

1987.

28. In Louisiana, parishes are the equivalent of counties. I combine the independent cities of Virginia

with their surrounding counties.

29. K. Terlouw, Transnational regional development in the Netherlands and Northwest Germany, 1500-

2000, Journal of Historical Geography 35(2009) 26-43.

30. Rappaport and Sachs, The United States as a coastal nation, page 9.

31. E. L. Glaeser, Learning in cities, Journal of Urban Economics 46 (1999) 254-277.

32. D. Acemoglu, S. Johnson, and J. A. Robinson. Reversal of fortune: geography and institutions in the

making of the modern world income distribution, Quarterly Journal of Economics 117(2002) 1231-1294.

33. R. E. Gallman, The agricultural sector and the pace of economic growth: U.S. experience in the

nineteenth century, in: D. C. Klingaman and R. K. Vedder (Eds.), Essays in Nineteenth Century

Economic History: The Old Northwest, Athens, OH, 1975, 35-76.

34. C. A. Dimitri, A. Effland, and N. Conklin, The 20th Century Transformation of U.S. Agriculture and

Farm Policy, United States Department of Agriculture, Economic Research Service, Economic

Information Bulletin Number 3, June 2005.

35. County boundary maps are from Minnesota Population Center, National Historical Geographic

Information System: Version 2.0, Minneapolis, MN, 2011. Web. 12 January 2013.

<https://www.nhgis.org/>.

36. R. A. Easterlin, Farm production and income in old and new areas at mid-century, in: D. C.

Klingaman and R. K. Vedder (Eds.), Essays in Nineteenth Century Economic History: The Old

Northwest, Athens, OH, 1975, 99.

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37. P. Krugman, Increasing returns and economic geography, Journal of Political Economy 99(1991)

483-499.

38. M. Kilkenny, Transport costs and rural development, Journal of Regional Science 38(1998) 293-312.

39. D. R. Meyer, The Roots of American Industrialization, Baltimore, 2003.

40. S. W. Fletcher, Pennsylvania Agriculture and Country Life, 1840-1940, Harrisburg, PA, 1955.

41. K. Chen and J. K. Pasto, Facts on a Century of Agriculture in Pennsylvania 1839 to 1950, State

College, PA, 1955.

42. Fletcher, Pennsylvania Agriculture and Country Life, page 2.

43. M. L. Nerlove and E. Sadka, Von Thunen’s model of the dual economy, Journal of Economics

54(1991) 97-123.

44. Krugman, Geography and Trade; Kim, Expansion of markets and the geographic distribution of

economic activities.

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Table 1

Agriculture Density Metrics and Sources

Year Variable Data Source

1820 persons engaged in agriculture 1820 Census

1830 - -

1840 persons engaged in agriculture 1840 Census

1850 value of livestock, animals slaughtered, orchard

products, and produce of market gardens

1850 Census

1860 value of livestock, animals slaughtered, orchard

products, and produce of market gardens

1860 Census

1870 estimated value of all farm products 1870 Census

1880 estimated value of all farm products 1880 Census

1890 estimated value of all farm products 1890 Census

1900 estimated value of all farm products 1900 Census

1910 total value of all crops 1910 Census

1920 total value of all crops 1920 Census

1930 total value of all crops 1930 Census

1940 total value of all crops 1940 Census

1950 value of farm products sold in 1949 1952 County and City Data Book

1960 value of farms products sold in 1959 1962 County and City Data Book

1970 value of farms products sold in 1969 1972 County and City Data Book

1980 value of farm products sold in 1982 1988 County and City Data Book

1990 value of farm products sold in 1987 1994 County and City Data Book

2000 market value of agricultural products sold in 2002 2002 Census of Agriculture

2010 market value of agricultural products sold in 2007 2007 Census of Agriculture

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Table 2.

Manufacturing Density Metrics and Sources

Year Variable Data Source

1820 persons engaged in manufacturing 1820 Census

1830 - -

1840 total capital invested in manufacturing 1840 Census

1850 annual value of products in manufacturing 1850 Census

1860 annual value of products in manufacturing 1860 Census

1870 annual value of products in manufacturing 1870 Census

1880 annual value of products in manufacturing 1880 Census

1890 annual value of products in manufacturing 1890 Census

1900 annual value of products in manufacturing 1900 Census

1910 - -

1920 annual value of products in manufacturing 1920 Census

1930 annual value of products in manufacturing 1930 Census

1940 annual value of products in manufacturing 1940 Census

1950 value added by manufacture in 1947 1952 County and City Data Book

1960 value added by manufacture in 1958 1967 County and City Data Book

1970 value added by manufacture in 1972 1977 County and City Data Book

1980 value added by manufacture in 1982 1988 County and City Data Book

1990 value added by manufacture in 1987 1994 County and City Data Book

2000 value added by manufacture in 2002 2002 Economic Census

2010 value added by manufacture in 2007 2007 Economic Census

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Table 3.

Gini Coefficients for the Density of Economic Activity

Year Population Agriculture Manufacturing

1820 0.604 0.449 0.825

1830 0.645

1840 0.640 0.453 0.917

1850 0.661 0.465 0.950

1860 0.701 0.409 0.943

1870 0.690 0.454 0.946

1880 0.708 0.441 0.960

1890 0.731 0.411 0.964

1900 0.734 0.390 0.949

1910 0.762 0.359

1920 0.819 0.381 0.962

1930 0.830 0.366 0.963

1940 0.827 0.387 0.957

1950 0.835 0.455 0.953

1960 0.834 0.441 0.937

1970 0.831 0.463 0.898

1980 0.804 0.481 0.879

1990 0.802 0.503 0.870

2000 0.796 0.523 0.811

2010 0.794 0.556 0.798

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Table 4.

Spearman's Rank Correlations

Population

1820 1890 1950

1830 0.959

1840 0.870

1850 0.803

1860 0.722

1870 0.638

1880 0.610

1890 0.553

1900 0.506 0.977

1910 0.474 0.923

1920 0.452 0.864

1930 0.425 0.807

1940 0.404 0.779

1950 0.418 0.761

1960 0.436 0.747 0.979

1970 0.451 0.715 0.925

1980 0.452 0.684 0.895

1990 0.471 0.661 0.858

2000 0.478 0.637 0.823

2010 0.488 0.627 0.811

Agriculture

1820 1890 1950

1840 0.696

1850 0.633

1860 0.505

1870 0.404

1880 0.388

1890 0.368

1900 0.357 0.934

1910 0.346 0.873

1920 0.298 0.744

1930 0.264 0.652

1940 0.308 0.716

1950 0.318 0.696

1960 0.272 0.653 0.934

1970 0.185 0.572 0.863

1980 0.135 0.511 0.827

1990 0.121 0.497 0.793

2000 0.109 0.423 0.699

2010 0.068 0.426 0.690

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Manufacturing

1820 1890 1950

1840 0.648

1850 0.686

1860 0.635

1870 0.562

1880 0.570

1890 0.501

1900 0.477 0.893

1920 0.352 0.751

1930 0.327 0.738

1940 0.367 0.744

1950 0.423 0.722

1960 0.425 0.714 0.880

1970 0.410 0.649 0.805

1980 0.403 0.603 0.748

1990 0.367 0.565 0.682

2000 0.359 0.569 0.701

2010 0.391 0.622 0.759

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Figure 1. Gini Coefficients for Population Density

Figure 2. Gini Coefficients for Manufacturing Density

Figure 3. Gini Coefficients for Agricultural Density

Figure 4. Agriculture-Dense Counties in 1820

0.6

0.65

0.7

0.75

0.8

0.85

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

Year

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Figure 2. Gini Coefficients for Manufacturing Density

0.75

0.8

0.85

0.9

0.95

1

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

Year

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Figure 3. Gini Coefficients for Agricultural Density

0.35

0.4

0.45

0.5

0.55

0.6

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

Year

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Figure 4. Agriculture-Dense Counties in 1820

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Figure 5. Manufacturing-Dense Counties in 1820

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Figure 6. Agriculture-Dense Counties in 1890

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Figure 7. Manufacturing-Dense Counties in 1890

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Figure 8. Agriculture-Dense Counties in 1950

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Figure 9. Manufacturing-Dense Counties in 1950

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Figure 10. Agriculture-Dense Counties in 2010

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Figure 11. Manufacturing-Dense Counties in 2010

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Figure 12. Correlation Coefficients Between Agricultural and Manufacturing Densities

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

Year