Was the study controlled for the age of the parents and/or the income levels at the times of various levels of giving? I am a graduate of a school with one of the largest and most active alumni associations, but as a graduate student pursuing two terminal degrees (MD and PhD), I clearly lack the income to donate significantly to my alma mater. By the time I finish residency, pay off my loans, and have the salary to afford greater charity, my kids will be in their teen years. Thus, my charity may appear to be for my children's admissions benefits. I am not alone in this late-peaking career trajectory, especially among the graduates of more prestigious schools, so without proper controls, this could greatly skew the results.