"This paper discusses conceptual and practical problems involved in constructing a cross-national list of ethnic groups (sections 2 and 3) and then presents the results of an effort to carry out the task (sections 4-8). Restricting attention to groups that had at least 1% of country population in the 1990s, I identify 820 ethnic and “ethnoreligious” groups in 160 countries." (Quoted from paper)