Thought Leadership

We build on AGM belief revision (Alchourrón et al. (1985)) and propose a class of updating rules called pragmatic rules. Pragmatic updating applies to multiple priors and requires that the agent's posteriors be the subset of her priors under which the realized event occurs with probability 1, if such priors exist. We construct a propositional language based on qualitative probability and demonstrate the strong relation between belief updating rules and belief revision rules in this language. We show that an updating rule is consistent with AGM belief revision if and only if it is pragmatic. While maximum likelihood updating is pragmatic in general, full-Bayesian updating is not. We characterize maximum likelihood updating within the AGM framework, and show that full-Bayesian updating can be obtained by dropping one of AGM's postulates.

We introduce a learning model in which the decision maker does not know how recommendations are generated, called the contraction rule. We present behavioral postulates that characterize it. The contraction rule can be uniquely identified and reveals how the decision maker interprets and how much she trusts the recommendation. In a dynamic stationary setting, we show that the contraction rule is not dominated by completely following recommendations and is incompatible with a property called compliance with balanced recommendations. Following this negative result, we demonstrate that the contraction rule may generate and reinforce recency bias and disagreement.

We study how proprietary information flows in strategic alliances facilitate banks’ information collection in private debt markets. We argue that lenders that have previously worked with a borrower’s alliance partners have an information advantage and show that firms entering a strategic alliance receive a lower interest spread on loans from banks that have previously lent to their strategic partners than loans from other banks. Cross-sectional tests on alliances’ economic importance and participants’ information environment support our hypothesis that the loan price effect is driven by reduced information asymmetry between borrowers and their partners’ relationship banks. Last, we find borrowers are more likely to obtain debt financing from alliance-related banks than from other banks. Overall, our findings are consistent with lenders that have previously worked with an alliance counterparty possessing debt contracting-relevant information about the soft nature of alliance value and the partners’ commitment to alliances.