NBER Publications by Toshihiko Mukoyama

We analyze a Bewley-Huggett-Aiyagari incomplete-markets model with labor-market frictions. Consumers are subject to idiosyncratic employment shocks against which they cannot insure directly. The labor market has a Diamond-Mortensen-Pissarides structure: firms enter by posting vacancies and match with workers bilaterally, with match probabilities given by an aggregate matching function. Wages are determined through Nash bargaining. We also consider aggregate productivity shocks, and a complete set of contingent claims conditional on this risk. We use the model to evaluate a tax-financed unemployment insurance scheme. Higher insurance is beneficial for consumption smoothing, but because it raises workers' outside option value, it discourages firm entry. We find that the latter effect is m...

We develop a simple model featuring search frictions and a nondegenerate labor supply decision along the extensive margin. The model is a standard version of the neoclassical growth model with indivisible labor with idiosyncratic shocks and frictions characterized by employment loss and employment opportunity arrival shocks. We argue that it is able to account for the key features of observed labor market flows for reasonable parameter values. Persistent idiosyncratic productivity shocks play a key role in allowing the model to match the persistence of the employment and out of the labor force states found in individual labor market histories.

Commonly used frictional models of the labor market imply that changes in frictions have large effects on steady state employment and unemployment. We use a model that features both frictions and an operative labor supply margin to examine the robustness of this feature to the inclusion of a empirically reasonable labor supply channel. The response of unemployment to changes in frictions is similar in both models. But the labor supply response present in our model greatly attenuates the effects of frictions on steady state employment relative to the simplest matching model, and two common extensions. We also find that the presence of empirically plausible frictions has virtually no impact on the response of aggregate employment to taxes.

This paper analyzes a model that features frictions, an operative labor supply margin, and incomplete markets. We first provide analytic solutions to a benchmark model that includes indivisible labor and incomplete markets in the absence of trading frictions. We show that the steady state levels of aggregate hours and aggregate capital stock are identical to those obtained in the economy with employment lotteries, while individual employment and asset dynamics can be different. Second, we introduce labor market frictions to the benchmark model. We find that the effect of the frictions on the response of aggregate hours to a permanent tax change is highly non-linear. We also find that there is considerable scope for substitution between "voluntary" and "frictional" nonemployment in some sit...