In a major study of the role of institutions in politics, James G. March and Johan P, Olsen offer a simple proposition: Organization matters. If the organization stands too much in opposition to the external environment, it may not survive or make much of a political impact. Organized crime and gangs often impose a hierarchical structure that requires members to learn the organization's history rules, and norms before they can rise through its ranks. An organization's tendency toward formal or informal structure depends on five distinct factors: issues and goals, membership, resources, strategies, and environment. A movement with instrumental goals, limited contact with the external environment, and exclusive membership is likely to have a more formal structure and strong leadership. An influx of new members presents difficult challenges for protest organizations, just as it does for ordinary political organizations. The uncertainty of the political environment puts "intense stresses on the relational patterns within a social movement organization",.