Does research show the same effect of happiness on our work life? Here too, most research is cross-sectional. Thus, at any given time people with high levels of positive mood tend to have better jobs, higher income, and more autonomous and meaningful work than less happy people. Obviously, the chicken-and-egg problem is relevant here as well. Certainly, many people (if not most) have experienced the negative emotional effects of working at an unpleasant job at some point in their lives. Longitudinal research, however, shows that high levels of positive emotion early in life predicts occupational and financial success many years later. For example, Ed Diener and colleagues found in a 2002 study that college students who displayed more cheerfulness in their first year of college made more money sixteen years later than did their less cheerful counterparts. This effect was found regardless of family income. In fact, the effect was particularly pronounced with students from higher-income families. Presumably, these students had fewer barriers to occupational success than students from lower-income families. Consequently, their emotional state had that much more influence.