A parity-equity model for estimating the influences of rational and nonrational inequity and parity (marketplace) factors on faculty salaries were developed. A comprehensive list of factors was classified as rational equity (e.g., professorial rank, years in rank, years of experience), nonrational equity (e.g., sex, years at university), and marketplace (average salaries of faculty by rank, by college, and by department at eight other land-grant AAU institutions). In a multiple regression analysis, 61 percent of the variation in salaries of 922 faculty was explained by professorial rank; 16 percent by other rational equity factors; 2 percent by college parity; 1 percent by college affiliation; and 1 percent by nonrational equity factors. Neither college affiliation nor college or department parity was as important as the internal equity factors, with the rational equity factors as the most important. In total, 81 percent of the variance in salaries was accounted for by the parity-equity model. The issues in using this model to evaluate salary policies are discussed. The use of the model is recommended for studying the year-to-year changes in salaries policies but its use to determine possible discrimination in salary for an individual faculty member is problematic. (Author/LBH)