Serdar Ozkan, Jae Song, Fatih Karahan
We study the determinants of lifetime earnings (LE) inequality in the U.S. by focusing on latent heterogeneity in job ladder dynamics and on-the-job learning as sources of wage growth differentials. Using administrative data, we find (i) more frequent job switches among lower LE workers, mainly driven by nonemployment spells, (ii) little heterogeneity in average annual earnings growth of job stayers in the bottom two-thirds of the LE distribution, and (iii) an earnings growth for job switchers that rises strongly with LE. We estimate a structural model featuring a rich set of worker types and firm heterogeneity. We find vast differences in ex-ante job ladder risk—job loss, job finding, and contact rates—across workers. These differences account for 75% of the lifetime wage growth differential among the bottom half of the LE distribution. Above the median, almost all lifetime wage growth differences are a result of Pareto-distributed learning ability.
Fatih Guvenen, Serdar Ozkan, Rocio Madera
Recent empirical studies document that the distribution of earnings changes displays substantial deviations from lognormality: in particular, earnings changes are negatively skewed with extremely high kurtosis (long and thick tails), and these non-Gaussian features vary substantially both over the life cycle and with the earnings level of individuals. Furthermore, earnings changes display nonlinear (asymmetric) mean reversion. In this paper, we embed a very rich “benchmark earnings process” that captures these non-Gaussian and nonlinear features into a lifecycle consumption-saving model and study its implications for consumption dynamics, consumption insurance, and welfare. We show four main results. First, the benchmark process essentially matches the empirical lifetime earnings inequality—a first-order proxy for consumption inequality—whereas the canonical Gaussian (persistent-plus-transitory) process understates it by a factor of five to ten. Second, the welfare cost of idiosyncratic risk implied by the benchmark process is between two-to-four times higher than the canonical Gaussian one. Third, the standard method in the literature for measuring the pass-through of income shocks to consumption—can significantly overstate the degree of consumption smoothing possible under non-Gaussian shocks. Fourth, the marginal propensity to consume out of transitory income (e.g., from a stimulus check) is higher under non-Gaussian earnings risk.
Elin Halvorsen, Hans A. Holter, Serdar Ozkan, Kjetil Storesletten
This paper examines whether nonlinear and non-Gaussian features of earnings dynamics are caused by hours or hourly wages. Our findings from the Norwegian administrative and survey data are as follows: (i) Nonlinear mean reversion in earnings is driven by the dynamics of hours worked rather than wages since wage dynamics are close to linear, while hours dynamics are nonlinear—negative changes to hours are transitory, while positive changes are persistent. (ii) Large earnings changes are driven equally by hours and wages, whereas small changes are associated mainly with wage shocks. (iii) Both wages and hours contribute to negative skewness and high kurtosis for earnings changes, although hour-wage interactions are quantitatively more important. (iv) When considering household earnings and disposable household income, the deviations from normality are mitigated relative to individual labor earnings: changes in disposable household income are approximately symmetric and less leptokurtic.
Elin Halvorsen, Serdar Ozkan, Sergio Salgado
Using administrative data, we provide an extensive characterization of labor earnings dynamics in Norway. Some of our findings are as follows. (i) Norway has not been immune to the increase in top earnings inequality seen in other countries. (ii) The earnings distribution compresses in the bottom 90% over the life cycle but expands in the top 10%. (iii) The earnings growth distribution is left skewed and leptokurtic, and the extent of these nonnormalities varies with age and past income.
Fatih Guvenen, Fatih Karahan, Serdar Ozkan, Jae Song
Serdar Ozkan
I show that while the rich spend more on healthcare early in life, the poor outspend them by 25% from middle to old age in the US. Furthermore, the poor seek medical care less frequently but face higher risks of extreme expenses when they do. I develop a life-cycle model, incorporating physical and preventive health capital, along with features of the US healthcare system. Preventive health capital governs the distribution of health shocks, thereby controlling life expectancy. The model suggests that the rich spend more on preventive care due to lower marginal utility of consumption, resulting in milder health shocks and lower curative expenses in old age. Public insurance– covering large curative expenditures– inadvertently widens the life expectancy gap by hampering the poor’s incentives to invest in preventive health. Policy experiments suggest that expanding insurance coverage and subsidizing preventive care to encourage the poor to use healthcare early in life yield substantial welfare gains.
Aaron Hedlund, Kieran Larkin, Kurt Mitman, Serdar Ozkan
This paper examines the impact of mortgage market structures on shaping economic responses to the unprecedented interest rate and inflation dynamics of 2021-2024. We first empirically document that economies with a larger share of variable-rate mortgages exhibit stronger responses in house prices to monetary policy shocks. We then develop and calibrate a structural model of the housing market to demonstrate that these mortgage structures can account for a substantial portion of the divergent house price paths observed across the U.S., Canada, Sweden, and the U.K. during the Great Inflation. Our analysis reveals that early pandemic mortgage rate cuts drove 45% of the U.S. house price boom. Economies dominated by adjustable-rate mortgages (ARMs) show greater price sensitivity to monetary tightening, while fixed-rate mortgage (FRM) regimes exhibit more pronounced path dependence due to a lock-in effect. These dynamics have significant distributional consequences, with low-income homeowners benefiting most from the initial low-rate environment, especially in FRM regimes. Finally, we show that the preferred monetary tightening path is regime-dependent, as a policy counterfactual reveals that FRM-dominant economies benefit more from a shorter and sharper tightening schedule.
Fatih Karahan and Serdar Ozkan
How does the persistence of earnings change over the life cycle? Do workers at different ages face the same variance of idiosyncratic earnings shocks? This paper proposes a novel specification for residual earnings that allows for an age profile in the persistence and variance of labor income shocks. We show that the statistical model is identified, and we estimate it using Panel Study of Income Dynamics data. We find that shocks to earnings are only moderately persistent (around \(0.75\) ) for young workers. Persistence rises with age, up to unity, until midway through life. The variance of persistent shocks exhibits a U-shaped profile over the life cycle (with a minimum of \(0.01\) and a maximum of \(0.05\) ). These results suggest that the standard specification in the literature (with age-invariant persistence and variance) cannot capture the earnings dynamics of young workers. We also argue that a calibrated job turnover model can account for these nonflat profiles. The key idea is that workers sort into better jobs and settle down as they age; in turn, magnitudes of wage growth rates decline, thereby decreasing the variance of shocks. Furthermore, the decline in job mobility results in higher persistence. Finally, we investigate the implications of age profiles for consumption-savings behavior. The welfare cost of idiosyncratic risk implied by the age-dependent income process is up to \(1.6\) percent of lifetime consumption lower compared with its age-invariant counterpart. This difference is mostly due to a higher degree of consumption insurance for young workers, for whom persistence is moderate. These results suggest that age profiles of persistence and variances should be taken into account when calibrating life-cycle models.
Joachim Hubmer ⓡ Mons Chan ⓡ Serdar Ozkan ⓡ Sergio Salgado ⓡ Guangbin Hong
Are larger firms more productive, more scalable, or both? We use firm-level panel data from thirteen countries and employ a broad set of methods to estimate factor elasticities—capturing returns to scale (RTS)—and total factor productivity (TFP). We find substantial RTS heterogeneity within industries, with larger firms exhibiting higher RTS driven by greater intermediate input elasticities. TFP, by contrast, rises with firm size only up to the top decile before declining. The RTS–size gradient primarily reflects persistent, ex-ante differences in production technologies across firms rather than non-homothetic variation along a common production function. Incorporating RTS heterogeneity into a standard model of entrepreneurship more than doubles the efficiency losses from financial frictions compared with a conventional calibration with only TFP differences.
Fatih Guvenen, Burhanettin Kuruscu, Serdar Ozkan
Wage inequality has been significantly higher in the United States than in continental European countries (CEU) since the 1970s. Moreover, this inequality gap has further widened during this period as the US has experienced a large increase in wage inequality, whereas the CEU has seen only modest changes. This paper studies the role of labor income tax policies for understanding these facts, focusing on male workers. We construct a life cycle model in which individuals decide each period whether to go to school, work, or stay non-employed. Individuals can accumulate human either in school or while working. Wage inequality arises from differences across individuals in their ability to learn new skills as well as from idiosyncratic shocks. Progressive taxation compresses the (after-tax) wage structure, thereby distorting the incentives to accumulate human capital, in turn reducing the cross-sectional dispersion of (before-tax) wages. Consistent with the model, we empirically document that countries with more progressive labor income tax schedules have (i) significantly lower before-tax wage inequality at different points in time and (ii) experienced a smaller rise in wage inequality since the early 1980s. We then study the calibrated model and find that these policies can account for half of the difference between the US and the CEU in overall wage inequality and 84% of the difference in inequality at the upper end (log 90-50 differential). In a two-country comparison between the US and Germany, the combination of skill-biased technical change and changing progressivity of tax schedules explains all the difference between the evolution of inequality in these two countries since the early 1980s.
Fatih Guvenen, Serdar Ozkan, Jae Song
This paper studies business cycle variation in individual earnings risk using a unique and confidential dataset from the U.S. Social Security Administration, which contains (uncapped) earnings histories for millions of individuals. We document two sets of results. First, contrary to past research, we find that the variance of idiosyncratic earnings shocks is not countercyclical. Instead, it is the left-skewness of shocks that is strongly countercyclical: during recessions, the upper end of the shock distribution collapses—large upward earnings movements become less likely—whereas the bottom end expands—large drops in earnings become more likely. Thus, while the dispersion of shocks does not increase, shocks become more left skewed and, hence, risky during recessions. Second, we find that the fortunes during recessions are predictable by observable characteristics before the recession. For example, prime-age workers that enter a recession with high earnings suffer substantially less compared with those who enter with low earnings. Finally, the cyclical nature of earnings risk is dramatically different for the top 1% compared with all other individuals—even those in the top 2% to 5%.
Aakash Kalyani and Serdar Ozkan
We develop a novel measure of firm-level marginal labor cost and investigate its inflation pass-through. We apply textual analysis to earnings calls to identify labor discussions. Leveraging cost-minimization theory that firms equate marginal revenue products across variable inputs, we regress intermediate input revenue shares on labor discussion intensity to recover marginal labor cost shocks. This theory-based approach aggregates multidimensional qualitative information into a single measure. Our aggregate index outperforms conventional slack variables in forecasting inflation. Industry-level pass-through to prices is heterogeneous: highest for services, near-zero for manufacturing, where firm-level data reveal automation mitigates labor cost pressures.
Fatih Guvenen, Fatih Karahan, Serdar Ozkan, Jae Song
We study individual male earnings dynamics over the life cycle using panel data on millions of U.S. workers. Using nonparametric methods, we first show that the distribution of earnings changes exhibits substantial deviations from lognormality, such as negative skewness and very high kurtosis. Further, the extent of these non-normalities varies significantly with age and earnings level, peaking around age 50 and between the 70th and 90th percentiles of the earnings distribution. Second, we estimate nonparametric impulse response functions and find important asymmetries: Positive changes for high-income individuals are quite transitory, whereas negative ones are very persistent; the opposite is true for low-income individuals. Third, we turn to long-run outcomes and find substantial heterogeneity in the cumulative growth rates of earnings and the total number of years individuals spend nonemployed between ages 25 and 55. Finally, by targeting these rich sets of moments, we estimate stochastic processes for earnings that range from the simple to the complex. Our preferred specification features normal mixture innovations to both persistent and transitory components and includes state-dependent long-term nonemployment shocks with a realization probability that varies with age and earnings.
Joachim Hubmer ⓡ Elin Halvorsen ⓡ Sergio Salgado ⓡ Serdar Ozkan
We study the lifecycle dynamics of wealth inequality using 1993-2019 Norwegian administrative panel data on wealth and income. Employing a novel budget-constraint approach, we decompose the excess wealth of the top 0.1% households relative to the median between ages 45 and 64 into higher saving rates (36%), inheritances (31%), returns (28%), and labor income (5%). One-quarter of the wealthiest—the “New Money”—start with negative wealth on average but accumulate rapidly through high labor income and exceptionally high saving rates and returns. The “Old Money” inherit substantial wealth and grow it through above-average though more modest saving and returns. We use these dynamic facts to evaluate five standard wealth inequality models. Although these models match cross-sectional wealth concentration, they fail to reproduce the distinct dynamics of New and Old Money. A heterogeneous entrepreneurship model with decreasing returns to scale technology and nonhomothetic preferences is consistent with the observed dynamics.