This paper considers the wide class of problems in which a searcher can choose his sample size and whether or not to stop search at each of a sequence of decision points. Sequential search problems are the special cases in which the sample size chosen at each decision point is unity. Several properties of the optimal sample size sequence are established, with particular attention being paid to the effects of recall, decision horizons and fallback utilities. These properties yield necessary and sufficient conditions for the optimality of sequential search strategies within the class of problems considered. 1.

Expected value maximizing sequential search rules can be expressed in terms of reservation values. In search with learning the reservation value at any stage of the search is unknown until that stage is reached. Thus calculating ex ante (and subsequent) probabilities of search duration and the offer accepted is difficult if these probabilities are expressed in terms of reservation values. This paper shows, for a wide class of learning procedures, how re-expressing these probabilities in terms of fixed points allows their direct calculation and, thereby, calculation of the expected value of adaptive search. Examples and comparative statics results are presented.

[This paper presents general results on the existence and properties of expected-utility-maximizing search rules for problems in which searchers may choose both the number of periods in which samples are taken and the size of the sample taken in each period. These rules include fixed-sample-size rules and sequential rules as special cases. Also presented are conditions sufficient for sequential and fixed-sample-size rules to be optimal.]

Since the early 2000s, macroprudential policy has increasingly become part of the regulatory and supervisory framework. Likewise, the housing market has been at the center of the debate on systemic financial risk prevention. Among macroprudential tools, the purpose of the loan-to-value (LTV) ratio is to constrain mortgage loan creation. This paper is unique in that it analyzes the effectiveness of LTV on mortgage lending moderation using a large sample of more than 4000 banks from 46 countries. The analysis suggests mortgage loans have been successfully curbed in countries with a LTV policy. Size and non-performing loans are the two key characteristics to the effectiveness of LTV. When nonlinearities are considered, the average effect of LTV can be very large; however, it becomes much less effective with large banks and banks with bad loans. Our results suggest the inclusion of other macroprudential tools may have complementary effects to LTV, and for large size banks in particular.