Andrew Fogg

Sex, drugs and data: UK GDP Redux

Friday 27 June 2014presented by

this talk is mainly about sex

and data

no drugs I am afraid

let’s start with a question

how much does prostitution contribute to the UK economy?

£1bn?

£2bn?

£5.314bn

0.4% GDP

£5.314bnthat is a big number

bigger than the entire economy of Moldova

bigger than 28% of global economies

but it would only buy 45% of WhatsApp

restatement of accounts in line with EU accounting guidelines

“illegal transactions to which all parties consent should be included in national accounts”

this includes prostitution and sale of illegal drugs

how did the ONS calculate that number for prostitution?

very simple

there are lots of assumptions and the number of prostitutes relies on one study

tried to count all the prostitutes in London over 6 months in 2004

phoned every brothel and escort agency they could find advertised

estimated count of off-street prostitutes in London (plus estimate of on-street prostitutes from police)

7,000 (+115)

scaled out to the UK using population statistics

how reliable is that number? especially the scaling assumption?

time to look at some web data

many activities associated with prostitution are illegal in the UK

but paying for sex is actually legal

as a result prostitution sits in a grey area and is widely marketed on the web

built an API to AdultWork directory using Import.io

AdultWork is ranked 174 top site in UK by Alexa

searched for all sex workers based in the UK and downloaded the data

categorised each sex worker by location (London / not London)

counted the number of London based prostitutes and estimated the UK total using scale assumption

then counted the number of UK based prostitutes on AdultWork

it seems that the scaling assumption is reasonable

so the ONS numbers are good?

not quite

what is wrong with this picture?

there are no men

“no information is included regarding men working in the sex industry”

40% of the prostitutes on AdultWork are men (in London and across UK)

recalculating GDP to take into account male prostitution gives a dramatic increase

£8.856bnnew number

0.6% GDP

the new total is bigger than the entire economy of Iceland

bigger than 37% of global economies

but it would still only buy 75% of WhatsApp

this is only a preliminary analysis

but i just added £3.542bn to the UK economy

plan to investigate further by examining the price per visit (data is also available on the web)

benefit of using web data for this kind of analysis is that it is up to date and can be tracked