The encyclopedia · R&D & Science · Operational decision · 1998–1999
Psychology internships ended the offer wars with one deferred-acceptance match
APPIC replaced its chaotic Uniform Notification Day with the Roth-Peranson matching algorithm, so no applicant hoards offers and no program fills up early.
APPIC · National Matching Services
the move
Psychology doctoral internships used to be allocated on a chaotic 'Uniform Notification Day' when programs phoned offers and applicants had to answer immediately. Students hoarded offers, held them in fear, or accepted a worse program to end the anxiety, and some programs over-offered then reneged.
In May 1998 the APPIC membership voted to replace this with a computerized Matching Program, effective with the 1999 Match run by National Matching Services. Its core is the Roth-Peranson algorithm, a deferred-acceptance algorithm adapted for real markets by Alvin Roth and Elliott Peranson.
Applicants and programs each submit their true ranked preferences and the system returns a stable, strategy-proof match. Because everything is resolved simultaneously from stated preferences, no participant can gain by misranking or by waiting, and programs cannot accidentally over-fill.
why it works
- The deferred-acceptance algorithm is stable: no applicant and program that would both prefer each other are left unmatched, so neither side gains by gaming.
- Solving the match simultaneously from full preference lists removes the payoff to hoarding offers or pressuring the other side.
- The mechanism is strategy-proof, so participants can honestly report preferences instead of speculating about what the other side will do.
- It was operated by a specialist firm that already ran similar matches across dentistry, pharmacy, optometry and podiatry.
what transfers
A market that fails through offer wars and premature commitments is fixed by replacing the deadline scramble with a simultaneous, stable, strategy-proof match, not by more rules on the old process.
what came after
The APPIC Match has been used every year since 1999 and remains the way psychology internships are filled. The same Roth and Peranson design underpins a family of professional matches, and the underlying deferred-acceptance method was central to the work that helped earn Alvin Roth the 2012 Nobel Prize in economics.
references
- Frequently Asked Questions: Introduction to the APPIC Match
- APPIC Match FAQs: Training Directors - Matching Process and Results
spotted an error? The archive wants to know.