To advance our understanding of diversity and inclusion in labor markets, this field experiment will examine the effects of workplace diversity on worker behavior and employee composition, and identify channels driving the effects, using actual workers in a real workplace. Employee diversity, defined as demographic variation among workers (primarily race and gender), has been argued to have significant impacts on worker- and firm-level outcomes such as employee behavior, recruiting, and productivity of companies and organizations. Yet much of this is theoretical and conjectural: rigorous empirical evidence on the existence and extent of impacts, as well as the causal mechanisms through which they occur, is lacking. This field experiment fills that gap by generating new causal evidence that tests for effects, measures their size, and identifies their channels. Specifically, the project will examine the impacts of racial diversity and gender diversity among workers on diversity and skill level of applicants, worker performance, labor supply, and other critical dimensions of worker behavior and characteristics. It will also identify the extent to which these impacts derive from (i) effects on the types of people that apply to a job (e.g. what types of workers are attracted to diverse or inclusive workplaces); (ii) effects on the types of people that stay at the firm (employee retention); and (iii) effects on behavior from working in a diverse or inclusive environment separate from impacts on types of employees recruited or retained. (The first two channels are often referred to as “selection effects” and the third as “treatment effects”.) Tightly linking the experiment design to a structural model will ensure the insights we uncover feed directly into our existing body of knowledge and help expand theory to better address questions and problems relating to diversity and inclusion.