The ratio of tax revenues to GDP rose in 21 of the 30 countries for which 2012 data is available, and fell in only 9 countries. The number of countries with increasing and decreasing ratios was similar to that seen in 2011, indicating a continuing trend toward higher revenues.

The largest increases in 2012 occurred in Hungary, Greece, Italy and New Zealand. The largest falls were in Israel, Portugal and the United Kingdom.

The increase in tax ratios between 2011 and 2012 is due to a combination of factors. In progressive tax regimes, revenue rises faster than income during periods of real income growth. Discretionary tax changes have also played a role, as many countries raised tax rates and/or broadened tax bases. Discretionary tax changes played a greater role in a handful of European countries where GDP levels actually declined in 2012.

The new data point to rising revenues in central, state and regional governments following the declines in 2008 and 2009, whereas the average tax ratio for local governments has remained steady since 2007.

The average tax burden in OECD countries increased by 0.5 percentage points, to 34.6% in 2012. This followed rises of 0.2 and 0.3 percentage points in 2010 and 2011, reversing the decline from 35% to 33.6% between 2007 and 2009. This is still below the most recent peak year of 2007 when tax revenues to GDP ratios averaged 35%.

Between 2011 and 2012, the largest tax ratio increases were in Hungary (1.8 percentage points) and in Greece (1.6 points). Other countries with substantial rises in their tax to GDP ratio between 2011 and 2012 were Italy and New Zealand (1.4 points), plus Belgium, France and Iceland (1.2 points).

The largest fall was in Israel with a decline from 32.6% to 31.6%. Portugal and the United Kingdom showed falls of 0.5 percentage points.

The increase in the United States, from 24.0% of GDP in 2011 to 24.3% in 2012, was lower than that seen in the OECD area.