In this study a model of the determination of individual votes in National Labor Relations Board representation elections was developed and estimated. The major conclusions fall into four areas. First, the perceived advantage of unionization is inversely related to the individual's position in the intrafirm earnings distribution. Second, explicitly measured perceptions of the impact of unionization on the nonwage aspects of the job are important determinants of the vote. Third, concern for the impact of unionization on job security is an important aspect of the unionization decision. Finally, it was found that after controlling for the effects of unionization on various aspects of the employment relationship, blacks are more likely and older workers are less likely to vote for unionization.