Ellison points to a "shrinking market" in the Cambridge area, due to the conversion of rental properties to private ownership, as exacerbating the already-bad problem.
The number of mid-Cambridge rentals advertised through HPRE is down by around 40 percent over the last year, he says.
According to Keller, HPRE is looking outside of Cambridge because of restrictions like the Red Line Agreement, a contract the city negotiated in the 1960s to prevent Harvard from over-extending its residential campus. The contract said that Harvard would not build or purchase residential property in Cambridge outside of a closely delineated area.
Although the piece of paper has expired, Power says Harvard still honors the agreement.
"It continues to be an interest of ours to respect the wishes of the city," she says.
--Staff writer Zachary R. Heineman can be reached at heineman@fas.harvard.edu.