“…Rust (1994) showed that DDC models are not identified nonparametrically, and Magnac and Thesmar (2002) characterized the degree of underidentification. Important advances that followed include (but are not limited to) Heckman and Navarro (2007), Pesendorfer and Schmidt-Dengler (2008), Blevins (2014), Bajari, Chu, Nekipelov, and Park (2016), and Abbring and Daljord (2019). In terms of estimation, Rust (1987) introduced the nested fixed point maximum likelihood estimator in his seminal contribution, and Hotz and Miller (1993) pioneered a computationally convenient two-step estimator that was then further analyzed by a host of important studies (Hotz, Miller, Sanders, and Smith, 1994;Aguirregabiria andMira, 2002, 2007;Bajari, Benkard, and Levin, 2007;Pakes, Ostrovsky, and Berry, 2007;Pesendorfer and Schmidt-Dengler, 2008).…”