Lazear's Jack-of-all trades theory suggests that individuals with balanced skills are more likely to become entrepreneurs, and that balanced skills can be accumulated by studying a varied curriculum, working in a variety of functions, and working for a variety of employers. We reexamine the theory using a matched case-control sample, constructed from a professional networking website that controls for unobserved heterogeneity in employer and job characteristics. We find evidence that variety predicts entry into entrepreneurship, largely through its positive association with the likelihood of having certain specific skills. However, our analysis also demonstrates that attempts to identify the effects of skill variety on entrepreneurship are likely to be highly sensitive to sample construction and regression specification.JEL Classification Codes: J24, L26.