A 2003 paper from the Cornell Higher Education Research Institute outlines one method for calculating and tracking student transfers:
One of the central roles for the community college is to provide a low cost, accessible education for students working toward a bachelor’s degree. Their success in fulfilling this mission is a subject of some debate. Vital to this debate, however, is the ability to accurately measure the rate of transfer from 2-year to 4-year colleges. The current study uses a relatively new national database from the National Student Clearinghouse (NSC) that will assist in this process.
The current study shows how colleges can track almost all of their own students who transfer into both public and private college and across state lines using the NSC database. While the data has its own limitations, it is an improvement over existing methods for tracking transfers from 2-year to 4-year colleges in the U.S. When it is linked to state and institutional data, it can provide a powerful tool for understanding the nature of the transfer process. For purposes of illustration, the transfer records of two upstate New York community colleges are examined using such a linked database
Romano, R. M. and Wisniewski, M. (2003) Tracking community college transfers using national student clearinghouse data (CHERI Working Paper #36). Retrieved June 23, 2015, from Cornell University, ILR School site: http://digitalcommons.ilr.cornell.edu/cheri/16/