RT Article T1 Are U.S. cities underpoliced? Theory and evidence JF The review of economics and statistics VO 100 IS 1 SP 167 OP 186 A1 Chalfin, Aaron A2 McCrary, Justin LA English YR 2018 UL https://krimdok.uni-tuebingen.de/Record/1912460122 DO 10.1162/REST_a_00694