Johannes Spinnewijn

Department of Economics
London School of Economics, Houghton Street
London, WC2A 2AE

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NBER Working Papers and Publications

December 2015Inferring Risk Perceptions and Preferences using Choice from Insurance Menus: Theory and Evidence
with Keith Marzilli Ericson, Philipp Kircher, Amanda Starc: w21797
Demand for insurance can be driven by high risk aversion or high risk. We show how to separately identify risk preferences and risk types using only choices from menus of insurance plans. Our revealed preference approach does not rely on rational expectations, nor does it require access to claims data. We show what can be learned non-parametrically from variation in insurance plans, offered separately to random cross-sections or offered as part of the same menu to one cross-section. We prove that our approach allows for full identification in the textbook model with binary risks and extend our results to continuous risks. We illustrate our approach using the Massachusetts Health Insurance Exchange, where choices provide informative bounds on the type distributions, especially for risks, bu...
November 2015Information Frictions and Adverse Selection: Policy Interventions in Health Insurance Markets
with Benjamin R. Handel, Jonathan T. Kolstad: w21759
A large literature has analyzed pricing inefficiencies in health insurance markets due to adverse selection, typically assuming informed, active consumers on the demand side of the market. However, recent evidence suggests that many consumers have information frictions that lead to suboptimal health plan choices. As a result, policies such as information provision, plan recommendations, and smart defaults to improve consumer choices are being implemented in many applied contexts. In this paper we develop a general framework to study insurance market equilibrium and evaluate policy interventions in the presence of choice frictions. Friction-reducing policies can increase welfare by facilitating better matches between consumers and plans, but can decrease welfare by increasing the correlatio...
June 2009Capital Income Taxes with Heterogeneous Discount Rates
with Peter A. Diamond: w15115
With heterogeneity in both skills and discount factors, the Atkinson-Stiglitz theorem that savings should not be taxed does not hold. We consider a model with heterogeneity of preferences at each earnings level. With some assumptions on the equilibrium, a small savings tax on high earners and a small savings subsidy on low earners both increase welfare, regardless of the correlation between ability and discount factor. Key is that types who value future consumption less are more tempted to switch to a lower paid job. Extending Saez (2002), a uniform savings tax increases welfare if the correlation of skill with discount factor is su¢ ciently high. Some optimal tax results and empirical evidence to support the assumptions are presented.

Published: Peter Diamond & Johannes Spinnewijn, 2011. "Capital Income Taxes with Heterogeneous Discount Rates," American Economic Journal: Economic Policy, American Economic Association, vol. 3(4), pages 52-76, November. citation courtesy of

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