This two- to four-week problem asks students to consider the hypothesis that “money makes people happy.” Students investigate this hypothesis starting with computing the bivariate correlation between income and happiness in the General Social Survey (GSS), using SPSS. They can also test competing hypotheses about other variables (such as number of friends or education) that might be associated with happiness and that are measured in the GSS. Students are asked to articulate correlation and causation pathsâ€”in particular, to speculate about possible third variables that may account for one of the bivariate correlations they observed. For advanced students, the problem can continue by allowing them to use multiple regression to investigate third variable explanations. That is, after a lecture on multiple regression, students apply what they have learned, testing possible third variables that may account for their bivariate correlation. Students complete the project by writing an APA-style research report on their results.