Post-2000s, the face of town and gown relations has changed as the effects of agglomeration have increasingly been studied and understood in urban economics. University agglomeration, or clustering, occurs when a large amount of institutions of higher education all locate in the same geographical area. This shift has been an important one for town and gown relations, as increasingly relationships between universities and their surrounding communities is no longer bilateral but multilateral; no longer town and gown but town and gowns. Prominent examples of such agglomeration in the United States include the large numbers of colleges and universities located in the San Francisco Bay Area, contributing to the development of Silicon Valley, as well as the well-known Research Triangle located in North Carolina.