Past higher education fund-raising studies examining alumni giving across several institutions have had two main limitations. First, the multitude of independent variables used in these studies has made it difficult to determine whether past studies have discovered many different factors that influence levels of alumni gift revenue, or whether they have discovered a few common factors that have been represented by different sets of variables in each study. Second, past studies have failed to adequately describe causal mechanisms through which variables significantly related to gift revenue influence levels of gift revenue. The current study addresses the aforementioned limitations in creating an aggregate model of donor behavior for law school alumni. The study examines alumni giving at 41 ABA-approved law schools. The results indicate that four basic factors account for most (87 percent) of the variance in amounts of alumni annual fund revenue among different law schools. The four factors, listed in order of importance and shown with the variables that load highly on each factor, are the following: Factor l--"Institutional Quality" (variables are average LSAT scores of accepted law students; reputation of law school among professors at other law schools; reputation of law school's graduates among judges and practicing lawyers; average starting salaries of new graduates of the law school; total number of volumes in law library; number of volumes in law library divided by FTE enrollment;). Factor 2--"Institutional Size" (variables are: FTE law school enrollment; number of living law school alumni; number of FTE law faculty; total number of law school advancement staff people). Factor 3--"Relative Advancement Effort" (variables are: number of law school advancement staff people divided by number of living law school alumni; number of law school reunion classes solicited for special gifts each year). Factor 4--"Institutional Age" (variables are: age of law school; age of law school's parent institution). Differences between the factor structures for public and private law schools are examined. The study suggests possible causal mechanisms through which these four factors influence the amount of alumni gift revenue raised by each law school.