Changes in institutional research performance over time are examined to identify fluctuations and differences across five Carnegie types of institutions (research-I, research-II, doctoral-I, doctoral-II, and comprehensive-I). The focus is on whether certain types of institutions may be accumulating research advantage with respect to sponsored grant support and publication output. Three general indices of research output are included (changes in research orientation or potential, proportion of faculty receiving sponsored research support, and level of faculty publication productivity). An aggregate measure of total research output combines grants and publications. Data are from four national surveys of the American professoriate conducted in 1969, 1975, 1980, and 1988. Results suggest that: (1) changes in academic research performance spanning 20 years suggest that competition for academic research continues to be keen; (2) while research-I universities retain their dominant position, other types continue to contribute substantially to the academic research enterprise; (3) there is an increased emphasis on research at all types of institutions; and (4) research output indices have risen in all the categories examined. Tables and figures are included. Contains 28 references. (SM)