Visit the OECD income inequality database at https://stats.oecd.org/Index.aspx?DataSetCode=IDD
There you will see data on Gini coefficients for market income, gross income (before taxes) and disposable income (post taxes and transfers). There is more data for "Income definition until 2011" so you may prefer to use that.
Pick three countries for which data exists for the period 2007-2014. Choose age group "total population". It is ok if some years are missing. Also for some countries data for 2013 and 2014 may not exist, that is ok too.
Write a short essay and answer the following questions. Use graphs or tables to support your arguments. Make sure you clearly label the graphs.
1) Which countries have lower income inequality with respect to market income?
2) Given the data how would you measure the "effectiveness of transfers in reducing inequality".
3) Given the data how would you measure the "effectiveness of transfers and taxes in reducing inequality"
4) Given the data how would you measure the "effectiveness of taxes in reducing inequality".
5) How do countries rank with respect to effectiveness of transfers in reducing inequality?
6) How do countries rank with respect to effectiveness of transfers and taxes in reducing inequality?
7) How do countries rank with respect to effectiveness of taxes in reducing inequality?
8) Overall, which policy instrument seems more effective in reducing inequality, transfers or taxes?
9) Do you see any noticeable change in the effectiveness of policy instruments in reducing inequality after the crisis of 2008-2009?