The researchers adopted six assumptions to guide this study. First, the vocation shortage in the U.S. is not a temporary problem but part of a long- term trend shaped by basic social forces and manifest in other modern societies. Second, sociological research that is intended to be of service to the church must address practical topics, be grounded in reliable data, and susceptible of application. Third, research provides information only; it cannot tell church leaders how to respond to the problem. Fourth, the U.S. Catholic church is in the midst of a long process of transformation from an immigrant enclave to a mainstream middle-class church, and particular attention should be payed to Episcopalians and Lutherans, the groups which tomorrow's Catholics will probably most resemble. Fifth, the priest shortage is an institutional rather than a spiritual or cultural problem. Finally, parishes will continue to form the backbone of Catholic religious life, and they will continue to require trained leadership. Hoge believes that there are four options for the U.S. Catholic church. First, the need for priests could be reduced, either by combining parishes or by encouraging the laity to lower their expectations of priestly services. Second, the number of clergy could be increased while maintaining present eligibility requirements, either by redistributing priests more effectively, drawing on religious orders, attracting priests from foreign nations, or recruiting more seminarians. Third, more priests could be attracted with altered eligibility requirements, either by opening ordination to married men and/or women, by instituting terms of service, or by utilizing resigned priests as sacramental ministers. Fourth, the ministries of the diaconate or laity (or both) could be expanded.