Designing a good unemployment insurance scheme is a delicate matter. In a system with no or little insurance, households may be subject to a high income risk, whereas excessively generous unemployment insurance systems are known to lead to high unemployment rates and are costly both from a fiscal perspective and for society as a whole. Andreas Pollak investigates what an optimal unemployment insurance system would look like, i.e. a system that constitutes the best possible compromise between income security and incentives to work. Using theoretical economic models and complex numerical simulations, he studies the effects of benefit levels and payment durations on unemployment and welfare. As the models allow for considerable heterogeneity of households, including a history-dependent labor productivity, it is possible to analyze how certain policies affect individuals in a specific age, wealth or skill group. The most important aspect of an unemployment insurance system turns out to be the benefits paid to the long-term unemployed. If this parameter is chosen too high, a large number of households may get caught in a long spell of unemployment with little chance of finding work again. Based on the predictions in these models, the so-called "Hartz IV" labor market reform recently adopted in Germany should have highly favorable effects on the unemployment rates and welfare in the long run.

Search Theory and Unemployment contains nine chapters that survey and extend the theory of job search and its application to the problem of unemployment. The volume ranges from surveys of job search theory that take microeconomic and macroeconomic perspectives to original theoretical contributions which focus on the externalities arising from non-sequential search and search under imperfect information. It includes a clear and authoritative survey of econometric methods that have been developed to estimate models of job search, as well as two lucid contributions to the empirical search literature. Finally, it includes a study that reviews and extends the literature on optimal unemployment insurance and concludes with an appraisal of the influence of search theory on the thinking of macroeconomic policymakers.

This book examines unemployment insurance policy through a survey, taking stock of the theoretical work in the field of labor economics. It closely follows and assesses developments in the modelling of optimal unemployment insurance (UI) policies, beginning with the initial analytical findings produced in the second half of the 1970s. A main part of the survey is devoted to the two basic strands of analysis about, respectively, the optimal level of UI benefits and the optimal time profile of UI policy. The book has two different objectives. The first is to provide an essential summary of the individual models, with the intention of underscoring how a number of specific messages for the policy-maker can be derived from analytical constructions. It further emphasizes and comments on what the models deliver to UI policy-makers. The second objective is to stress the importance and extension of open questions in the field of the theoretical approach to the unemployment insurance issue. The survey discusses the multiplicity of heterogeneities of the labor world in particular as relevant for UI issues on the one side, and on the other hand, the independence of the two basic choices of UI policy, its meaning and its limits, and the possible forms of complementarity between these choices. The book is a must-read for researchers, students, and policy-makers interested in a better understanding of the field of labor economics in general, as well as unemployment insurance policies in particular.

Abstract: This paper analyzes optimal unemployment insurance over the business cycle in a search model in which unemployment stems from matching frictions (in booms) and job rationing (in recessions). Job rationing during recessions introduces two novel effects ignored in previous studies of optimal unemployment insurance. First, job-search efforts have little effect on aggregate unemployment because the number of jobs available is limited, independently of matching frictions. Second, while job-search efforts increase the individual probability of finding a job, they create a negative externality by reducing other jobseekers' probability of finding one of the few available jobs. Both effects are captured by the positive and countercyclical wedge between micro-elasticity and macro-elasticity of unemployment with respect to net rewards from work. We derive a simple optimal unemployment insurance formula expressed in terms of those two elasticities and risk aversion. The formula coincides with the classical Baily-Chetty formula only when unemployment is low, and macro- and micro-elasticity are (almost) equal. The formula implies that the generosity of unemployment insurance should be countercyclical. We illustrate this result by simulating the optimal unemployment insurance over the business cycle in a dynamic stochastic general equilibrium model calibrated with US data

In an influential paper, Baily (1978) showed that the optimal level of unemployment insurance (UI) in a stylized static model depends on only three parameters: risk aversion, the consumption-smoothing benefit of UI, and the elasticity of unemployment durations with respect to the benefit rate. This paper examines the key economic assumptions under which these parameters determine the optimal level of social insurance. A Baily-type expression, with an adjustment for precautionary saving motives, holds in a very general class of dynamic models subject to weak regularity conditions. For example, the simple reduced-form formula derived here applies with arbitrary borrowing constraints, endogenous insurance markets, and search and leisure benefits of unemployment. A counterintuitive aspect of this result is that the optimal benefit rate appears not to depend on (1) any benefit of UI besides consumption-smoothing or (2) the relative magnitudes of income and substitution effects in the link between UI benefits and durations. However, these parameters enter implicitly in the optimal benefit calculation, and estimating them can be useful in testing whether the values of the primary inputs are consistent with observed behavior.