1. ? 0 (29) Which yields monotonicity. Next, the integrability condition, 1. follows from the fact that the utility itself is independent of c i and the application of Milgrom & Segal;I Kattwinkel;28) Rearrange (? i ? ? i )(X(? i , c i ) ? X(? i , c i )),2002
2. Optimal allocation with costly verification;E Ben-Porath;American Economic Review,2014