Not sure if it explains everything though. The comparison may not be fair, but the tax rates in US ~ the 50s and 60s were fairly high too, and yet it led to post-WW2 boom:

Dwight D. Eisenhower

Marginal Tax Rate on Regular Income over $400,000: 92% - 91%

Maximum Tax Rate on Long-Term Capital Gains: 25%

Source: http://news.yahoo.com/eisenhower-obama-wealthiest-americans-...