Personal income tax represented around 8.5% of GDP in the OECD countries in 2010, down from more than 10% in 1990. Personal income taxes have been declining since the mid 1980s when marginal tax rates started being cut in most countries.
While 70% marginal personal income tax was not uncommon in the late 1970s, these rates are now well below 50% in a majority of OECD countries. Since 2000, top rates have been further reduced by 7% or more in 12 countries and only a few countries have raised their top rate (e.g. Portugal and the United Kingdom) as part of recent fiscal consolidation tax measures.
Scandinavians contribute traditionally the most from their own pockets to the state coffers (over 11% of GDP), but Denmark (where personal income taxes form a quarter of GDP) clearly stands out here.
Helgi Library 
