Estimates of the size of the shadow economy in 21 OECD countries are
presented. The average size of the shadow economy (as a percentage of ‘official’
GDP) over 1999/2000 in these countries is 16.7%. The author concludes that it is
the increasing burden of taxation and social security contributions, combined
with rising state regulatory activities, that are the driving forces for the recent growth in size of the shadow economy in the countries concerned.