The search for capital adequacy in the mortgage market: a case of black swan blindness

Abstract

Purpose -The primary purpose of this paper is to review and critique Taleb's notion of black swan blindness for a subset of the broader field of financial economics -the search for capital adequacy rules for financial institutions who invest in residential mortgages. This search entails the analysis and prediction of extreme events in housing and mortgage markets. Design/methodology/approach -The focus of this paper concerns efforts to assess the likelihood and consequences of extreme and consequential economic events prior to their occurrence. The goal is to assess the criticism offered by Taleb that economists overstate the understanding of extreme events. One piece of evidence consists of a case study of the literature and policies regarding capital adequacy for financial institutions who invest in residential mortgages. The other is a review of recent literature about the crisis that offers similar conclusions. Findings -The evidence suggests that the criticism is valid. The case study reviews a number of areas in which the search for capital adequacy reflected the traits of black swan blindness as described by Taleb. The review of the recent literature about the crisis highlights a number of papers that reach similar conclusions. These include high level overviews of the literature on the crisis, e.g. Lo, a number of papers that specifically focus on housing and mortgage markets, and some very recent work about agent based modeling and complexity theory presented at the 2012 ARES meetings.Research limitations/implications -The conclusion suggests a number of ways in which economists can combat the potential of black swan blindness is our search for extreme events. One suggestion is to combat the error of confirmation with ongoing testing. Combating overly simplistic narratives can also be addressed by listening more carefully to the criticisms by people outside the field. Pay more attention to silent evidence by having more substantial and ongoing consumer testing of new products, more work to identify best practices, and more resources to enforce lending laws. Finally, more attention needs to be focused upon assumptions in the models that are based upon limited empirical evidence and, if found later to be false, may lead to dire outcomes. Practical implications -These include more and ongoing evaluation of stress tests. New rules to adjust capital requirements over the business cycle are consistent with the suggestions of the paper. Economists need to spend more time exploring and learning from outliers in the models. Social implications -The recent crisis has been driven by a wide variety of factors from within many sectors and agents. The outcome has been a major problem for people in many sectors and regions of the economy. The hope is that economists can do a better job in the future to help policymakers and others be more prepared for the potential of extreme events in the hopes of avoiding them in the future or at least reducing their likelihood and damage caused by them. Originality/value -The paper ...

US House Price Bubbles and Busts

“…Nicolas Taleb (2007) champions this idea in his book The Black Swan: The Impact of the Highly Improbable. Follain (2013) applies some of the concepts in Taleb's book to the issue of generating capital rules for extreme scenarios, concluding that Taleb's arguments have substantial merit.…”