“…1 Some examples include Cocco (2005) and Chetty, Laszlo, and Szeidl (2017), who studied the effects on portfolio choice; Ortalo-Magne and Rady (2006) and Favilukis, Ludvigson, and Van Nieuwerburgh (2017), who studied the effects on equilibrium prices and transactions; Corbae and Quintin (2015), who focused on foreclosures in the housing bust; Gete and Reher (2016), who studied the effects on homeownership; and Keys, Piskorski, Seru, and Yao (2014), who explored the role of housing in transmitting monetary policy. Under certain conditions, we can think of the possibility set of mortgage originations as analogous to a production possibility frontier, with borrower characteristics as inputs and contract terms as outputs.…”