Recently an important line of research using laboratory experiments has provided a new potential reason for why we observe gender imbalances in labor markets: men are more competitively inclined than women. Whether, and to what extent, such preferences yield differences in naturally-occurring labor market outcomes remains an open issue. We address this question by exploring job-entry decisions in a natural field experiment where we randomized nearly 7,000 interested job-seekers into different compensation regimes. By varying the role that individual competition plays in setting the wage, we are able to explore whether competition, by itself, can cause differential job entry. The data highlight the power of the compensation regime in that women disproportionately shy away from competitive work settings. Yet, there are important factors that attenuate the gender differences, including whether the job is performed in teams, whether the job task is female-oriented, and the local labor market.