2011 report from the Organisation for Economic Co-operation and Development on widening income inequalities among its member countries worldwide.

2011 study by the University of Wisconsin-Madison and Harvard University published in the online journal Plos ONE on impacts of poverty on child brain growth.

2010 study by the World Bank and Laval University for the Cairo-based Economic Research Forum on development and economic challenges in the Arab world

2008 paper by researchers from Harvard, MIT and Northwestern University on the potential effect of climate change on nations' economic growth.

2006 Princeton University study on the relationship between growing income inequality and increasing political divisions in the United States.

2009 RAND Corporation study on the disparities between Latino and African-American males and their white counterparts in California.

2010 Cornell University study done for the National Bureau of Economic Research on the effect of health insurance on trends in income inequality.

2008 University of California, San Francisco, study on the causes behind the high rate of dental care among the state's Latino children.

2009 National Bureau of Economic Research paper on the relationship between early exposure to violence and later problems such as substance abuse and delinquency.