Direct evidence has been lacking on entrepreneurs’ response to individual-specific opportunities, and recent work suggests that entrepreneurship may be a non-profit-seeking activity and that entrepreneurs evaluate risk oddly. We model heterogeneous inventors and inventions, outside opportunities, sunk and nonsunk costs, and risk, to guide data analysis. We use assessment data from a center paid to assess the inventions’ economic potential. Inventors’ choices whether to commercialize their inventions and later whether to remain in production were consistent with profit-seeking motives and risk aversion.