We find that returns to occupational tenure are substantial. Everything else being constant, 5 years of occupational tenure are associated with an increase in wages of 12% to 20%. Moreover, when occupational experience is taken into account, tenure with an industry or employer has relatively little importance in accounting for the wage one receives. This finding is consistent with human capital being occupation specific.JEL Classification: E24, J24, J31, J44, J62.

We document and analyze the high level and the substantial increase in worker mobility in the United States over the 1968-1997 period at various levels of occupational and industry aggregation. This is important in light of the recent findings in the literature that human capital of workers is largely occupation-or industry-specific. To control for measurement error in occupation and industry coding, we develop a method that utilizes the Retrospective Occupation-Industry Supplemental Data Files, newly released by the Panel Study of Income Dynamics. This allows us to obtain the most reliable estimates of occupational and industry mobility levels available in the literature. We emphasize the importance of these findings for understanding a number of issues such as the changes in wage inequality, aggregate productivity, job stability, and life-cycle earnings profiles.JEL classification: E20, E24, E30, J24, J44, J62.

In this study we argue that wage inequality and occupational mobility are intimately related. We are motivated by our empirical findings that human capital is occupation-specific and that the fraction of workers switching occupations in the United States was as high as 16% a year in the early 1970s and had increased to 19% by the early 1990s. We develop a general equilibrium model with occupation-specific human capital and heterogeneous experience levels within occupations. We argue that the increase in occupational mobility was due to the increase in the variability of productivity shocks to occupations. The model, calibrated to match the increase in occupational mobility, accounts for over 90% of the increase in wage inequality over the period. A distinguishing feature of the theory is that it accounts for changes in within-group wage inequality and the increase in the variability of transitory earnings. JEL Classification: E20, E24, E25, J24, J31, J62.

This paper studies the quantitative implications of wealth taxation (as opposed to capital income taxation) in an incomplete markets model with return rate heterogeneity across individuals. The rate of return heterogeneity arises from the fact that some individuals have better entrepreneurial skills than others, allowing them to obtain a higher return on their wealth. With such heterogeneity, capital income and wealth taxes have different efficiency and distributional implications. Under capital income taxation, entrepreneurs who are more productive and, as a result, generate more income pay higher taxes. Under wealth taxation, on the other hand, entrepreneurs who have similar wealth levels pay similar taxes regardless of their productivity. Thus, in this environment, the tax burden shifts from productive entrepreneurs to unproductive ones if the capital income tax were replaced with a wealth tax. This reallocation increases aggregate productivity. Second, and at the same time, it increases wealth inequality in the population. To provide a quantitative assessment of these different effects, we build and simulate an overlapping generations model with individual-specific returns on capital income and with idiosyncratic shocks to labor income. Our results indicate that switching from a capital income tax to a wealth tax increases welfare by almost 8% through better allocation of capital. We also study optimal taxation in this environment and find that, relative to the benchmark, the optimal wealth tax increases welfare by 9.6% while the optimal capital income tax increases it by 6.3%.

In this paper I highlight the importance of incorporating the institutional features of local labour markets into the analysis of trade reforms. A trade reform is often deemed beneficial because the elimination of trade barriers allows labour to reallocate towards those sectors in the economy in which the country has a comparative advantage. The amount and speed of the reallocation, however, and the post-reform behaviour of output, productivity and welfare, will depend on how regulated the labour market is. First, I document that high firing costs slow down the intersectoral reallocation of labour after a trade reform. Second, in order to isolate the effect of firing costs on labour reallocation, output and welfare after a trade reform, I build a dynamic general equilibrium model. I find that if a country does not liberalize its labour market at the outset of its trade reform, the intersectoral reallocation of workers will be 30% slower, and as much as 30% of the gains in real output and labour productivity in the years following the trade reform will be lost. From a policy standpoint, the message is that while trade reforms are desirable, they need to be complemented by labour market reforms in order to be fully successful.

We build a heterogeneous agents life cycle model that captures a large number of salient features of individual male labour supply over the life cycle, by education, both along the intensive and extensive margins. The model provides an aggregation theory of individual labour supply, firmly grounded on individual-level micro-evidence, and is used to study the aggregate labour supply responses to changes in the economic environment. We find that the aggregate labour supply elasticity to a transitory wage shock is 1.75, with the extensive margin accounting for 62% of the response. Furthermore, we find that the aggregate labour supply elasticity to a permanent-compensated wage change is 0.44.

The monthly Current Population Survey (CPS), with its annual demographic March supplement, and the Panel Study of Income Dynamics (PSID) are the leading sources of data on worker reallocation across occupations, industries, and firms. Much of the active current research is based on these data. In this paper, we contrast these data sets as sources of data for measuring the dynamics of worker mobility. We find that (i) (March) CPS data are characterized by a substantial amount of noise when it comes to identifying occupational and industry switches; (ii) March CPS data provide a poor measure of annual occupational mobility and, instead, most likely measure mobility over a much shorter period; (iii) (the changes in) the procedure to impute missing data have a dramatic effect on the interpretation of the CPS data in, e.g., the trend in occupational mobility. The most important shortcomings of the PSID are the facts that (i) occupational and industry affiliation data are available in most years at an annual frequency; (ii) the PSID's sample, by design, excludes immigrants arriving in the United States after 1968; (iii) the Retrospective Occupation-Industry Files with reliable occupation and industry affiliation data are available only until 1980.

There are substantial crosscountry differences in labor supply late in the life cycle (age 50+). A theory of labor supply and retirement decisions is developed to quantitatively assess the role of social security, disability insurance, and taxation for understanding differences in labor supply late in the life cycle across European countries and the United States. The findings support the view that government policies can go a long way towards accounting for the low labor supply late in the life cycle in the European countries relative to the United States, with social security rules accounting for the bulk of these effects.