Alan Krueger, top economic adviser to former President Barack Obama and one of the nation’s most influential labor market experts, took his own life over the weekend at the age of 58. Krueger was a labor economist and deeply involved in research that outlined the link between low labor force participation and addiction to opioid painkillers.

What Krueger discovered in his research was specifically related to men: “Prime-age men who are out of the labor force report that they experience notably low levels of emotional well-being throughout their days, and that they derive relatively little meaning from their daily activities.”