2008 study published in the Journal of Economic Perspectives on the factors that have hurt the U.S. pension-insurance corporation.

2010 study published in the Proceedings of the National Academy of Sciences on the potential cognitive benefits of regular aerobic exercise.

2010 study by researchers from the Harvard Medical School and others on the relationship between different amounts of physical activity and weight changes.

2009 paper in Circulation: Cardiovascular Quality and Outcomes examining the relationship between Medicare spending and outcomes for patients with heart failures

2009 RAND Corporation paper examines the potential benefits of workers remaining in the workforce for longer periods of time.

A 2008 paper for the National Bureau of Economic Research paper looking at age discrimination in the U.S. and the ADEA's historical effects

2008 study for the National Bureau of Economic Research on the effect of immigration on labor market outcomes for native elderly workers.