The National Resident Matching Program
Every year in March, hopeful medical school graduates are matched to hospital residency programs across the country through “The Match.” The Match is the National Resident Matching Program’s (NRMP) effort to optimize the medical student’s choice in residency program with the residency program’s preferences for applicants. The program was established in 1952 to better organize post graduate medical education assignments. Students will compile “rank-ordered lists” (ROL) of their preferred programs after interviewing, and residency programs will submit ROLs of their own in regards to their preferred applicants. The NRMP utilizes an algorithm to maximize the high ranks of both parties. Of course, there are many more students than there are spots, so the system matches to the best of its ability, with some remaining unmatched in the end.
The algorithm makes use of the theory of simple matching markets, and although the theory does not apply directly, it’s a good approximation. The residents are trying to be assigned to slots, which in this case is the hospital residency program. The situation strongly mirrors the “stable marriage problem.” The ROL’s compiled by the applicants and the hospitals are the input source for this algorithm. A matching is said to be stable when there is no alternative pairing that would put any individual in a more favorable assignment. A flaw of this current system, is that it sequentially balances the ranks of each pair, in such a way that it is ever so slightly possible that the assignments are affected by the order in which the applicants are entered. This effect, however, is negligible. The NRMP has proven that it is favorable for both parties to rank truthfully, and to make use of all rank positions you can possibly fill.
The aforementioned algorithm, however, does not include handling second-year positions, special unfilled residency positions, and special cases including “couples” (pairs of applicants who wish to be placed in the same geographic location). These special situations would tend to complicate the matching, and other means are used to accommodate for these cases.
- http://studentdoctor.net/2009/03/the-scramble-how-it-works-and-how-it-can-be-improved/
- http://www.bepress.com/cgi/viewcontent.cgi?article=1016&context=wilson
- http://www.nrmp.org/res_match/about_res/algorithms.html