Comparison is between a single individual and a married couple with two children.
France: 50.1% and 41.7%
UK: 33.5% and 27.1%
Canada: 31.6% and 21.5%
and
The United States of America 29.1% and 11.9%
This is a comparison of taxes paid by a household earning the country's average wage as of 2005. Source is the OECD.