We propose a highly tractable way of analyzing business cycles in an environment with random job search both off- and and on-the-job (OJS). Ex post heterogeneity in productivity across jobs generates a job ladder. Firms Bertrand-compete for employed workers, as in the Sequential Auctions protocol of Postel-Vinay and Robin (2002).We identify three channels through which OJS amplifies and propagates aggregate shocks: (i) a higher estimated elasticity of the matching function, when recognizing that at least half of all hires are from other employers; (ii) the differential returns to hiring employed and unemployed job applicants, whose proportions naturally vary over the business cycle; (iii) within employment, the slow reallocation of workers through OJS across rungs of the job ladder, generating endogenous, slowly evolving opportunities for further poaching, which feed back on job creation incentives.Endogenous job destruction, due to either aggregate or idiosyncratic shocks, is countercyclical and thus raises the cyclical volatility of unemployment, closer to its empirical value; but it also stimulates job creation in recessions, to take advantage of the fresh batch of unemployed, and tilts the Beveridge curve up. OJS corrects this tendency and restores a vacancy-unemployment trade-off more in line with empirical observations.

We revisit measurement of Employer-to-Employer (EE) transitions, the main engine of labor market competition and employment reallocation, in the monthly Current Population Survey (CPS). We follow Fallick and Fleischman (2004) and exploit a key survey question introduced with the 1994 CPS redesign. We detect a sudden and sharp increase in the incidence of missing answers to this question starting in 2007, when the U.S. Census Bureau introduced a change in survey methodology, the Respondent Identification Policy (RIP). We show evidence of selection into answering the EE question by both observable and unobservable worker characteristics that correlate with EE mobility. We propose a selection model and a procedure to impute missing answers to the key survey question, thus EE transitions, after the introduction of the RIP. Our imputed EE aggregate series restores a close congruence with the business cycle, especially with the onset of the Great Recession, exhibits a much less dramatic drop in 2008-2009 and a full recovery by 2016, and eliminates the spurious appearance of declining EE dynamism in the US labor market after 2000. We also offer the first evidence of the (large and negative) impact of the COVID-19 crisis on EE reallocation.

We introduce on-the-job search frictions in an otherwise standard monetary DSGE New-Keynesian model. Heterogeneity in productivity across jobs gives rise to a job ladder. Firms Bertrand-compete for employed workers according to the Sequential Auctions protocol of Postel-Vinay and Robin (2002). Outside job offers to employed workers, when accepted, reallocate employment up the productivity ladder; when declined, because matched by the current employer, they raise production costs and, due to nominal price rigidities, compress mark-ups, building inflationary pressure. When employment is concentrated at the bottom of the job ladder, typically after recessions, the reallocation effect prevails, aggregate supply expands, moderating marginal costs and inflation. As workers climb the job ladder, reducing slack in the employment pool, the inflation effect takes over. The model generates endogenous cyclical movements in the Neo Classical labor wedge and in the New Keynesian wage mark-up. The economy takes time to absorb cyclical misallocation and features propagation in the response of job creation, unemployment and inflation to aggregate shocks. The ratio between job-finding probabilities from job-to-job and from unemployment, a measure of the “Acceptance rate” of job offers to employed workers, predicts negatively inflation, independently of the unemployment rate.Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Many theories of labor market turnover generate a job ladder. Due to search frictions, workers earn rents from employment. All workers agree on which jobs are, in this sense, more desirable and slowly climb the job ladder through job-to-job quits. Occasionally, negative shocks throw them off the ladder and back into unemployment. We review a recent body of theory and empirical evidence on labor market turnover through the lens of the job ladder. We focus on the critical role that the job ladder plays in transmitting aggregate shocks, through the pace and direction of employment reallocation, to economic activity and wages and in shaping business cycles more generally. The main evidence concerns worker transitions, both through nonemployment and from job to job, between firms of different sizes, ages, productivity levels, and wage premiums, as well as the resulting earnings growth. Poaching by firms up the ladder is the main engine of reallocation, which shuts down in recessions.

We study the cyclical comovement nominal wage growth (either monthly earnings or hourly wage rate) and labor market flows. We use microdata from the Survey of Income and Program Participation over 1996-2013 to purge composition effects in worker and job characteristics and to isolate the reallocative effect of Employer-to-Employer (EE) transitions. We find an “EE wage Phillips curve”: wage inflation comoves positively with EE as strongly as with the employment rate. This correlation holds for job stayers; we interpret the EE rate as a measure of labor demand. We find no analogous evidence for the job-finding rate from unemployment.

We provide a quantitative exploration of business cycles in a frictional labor market under contract-posting. The steady-state random search and wage-posting model of Burdett and Mortensen (1998) has become the canonical structural framework for empirical analysis of worker turnover and equilibrium wage dispersion. In this paper, we provide an efficient algorithm to simulate a dynamic stochastic equilibrium version of this model, the Stochastic Burdett–Mortensen model, and evaluate its performance against empirical evidence on fluctuations in unemployment, vacancies and wages.

The canonical model of job search and wage posting (Burdett and Mortensen, 1998) establishes a natural connection between the average wage growth in the economy and the pace of Employer-to-Employer (EE) transitions, predicting wage growth to be positively related to the pace of EE reallocation for all workers, but especially for stayers. We verify this empirically both with aggregate time series and with longitudinal micro data from the Survey of Income and Program Participation (SIPP). We argue that monetary authorities concerned with inflationary wage pressure should pay more attention directly to EE reallocation and less to the unemployment rate.

We study employment reallocation across employers through the lens of a dynamic job ladder model. Workers always agree on a ranking of employers at all points in time and search for better jobs both off and on the job. A parsimonious version of the model fits well the time series of gross worker flows by employer size from newly available US data from the Job Openings and Labor Turnover Survey. Focusing on the US experience in and around the Great Recession, our evidence indicates that the job ladder stopped working then and has not fully resumed yet.

Using data from the Survey of Income and Program Participation (SIPP) covering 1990-2011, we document that a surprisingly large number of workers return to their previous employer after a jobless spell and experience more favorable labor market outcomes than job switchers. Over 40% of all workers separating into unemployment regain employment at their previous employer; over a fifth of them are permanently separated workers who did not have any expectation of recall, unlike those on temporary layoff. Recalls are associated with much shorter unemployment duration and better wage changes. Negative duration dependence of unemployment nearly disappears once recalls are excluded. We also find that the probability of finding a new job is more procyclical and volatile than the probability of a recall. Incorporating this fact into an empirical matching function significantly alters its estimated elasticity and the time-series behavior of matching efficiency, especially during the Great Recession. We develop a canonical search-and-matching model with a recall option where new matches are mediated by a matching function, while recalls are free and triggered by both aggregate and job-specific shocks. The recall option is lost when the unemployed worker accepts a new job. A quantitative version of the model captures well our cross-sectional and cyclical facts through selection of recalled matches. JEL Codes: E24, E32, J64

Using data from the Survey of Income and Program Participation (SIPP) covering 1990-2011, we document that a surprisingly large number of workers return to their previous employer after a jobless spell and experience more favorable labor market outcomes than job switchers. Over 40% of all workers separating into unemployment regain employment at their previous employer; over a fifth of them are permanently separated workers who did not have any expectation of recall, unlike those on temporary layoff. Recalls are associated with much shorter unemployment duration and better wage changes. Negative duration dependence of unemployment nearly disappears once recalls are excluded. We also find that the probability of finding a new job is more procyclical and volatile than the probability of a recall. Incorporating this fact into an empirical matching function significantly alters its estimated elasticity and the time-series behavior of matching efficiency, especially during the Great Recession. We develop a canonical search-and-matching model with a recall option where new matches are mediated by a matching function, while recalls are free and triggered by both aggregate and job-specific shocks. The recall option is lost when the unemployed worker accepts a new job. A quantitative version of the model captures well our cross-sectional and cyclical facts through selection of recalled matches.

We study equilibrium wage and employment dynamics in a class of popular search models with wage posting, in the presence of aggregate productivity shocks. Firms offer and commit to (Markov) contracts, which specify a wage contingent on all payoff-relevant states, but must pay equally all of their workers, who have limited commitment and are free to quit at any time. We find sufficient conditions for the existence and uniqueness of a stochastic search equilibrium in such contracts, which is Rank Preserving [RP]: larger and more productive firms offer more generous contracts to their workers in all states of the world. On the RP equilibrium path, turnover is always efficient as workers always move from less to more productive firms. The resulting stochastic dynamics of firm size provide an intuitive explanation for the empirical finding that large employers have more cyclical job creation (Moscarini and Postel-Vinay, 2012). Finally, computation of RP equilibrium contracts is tractable.

We document a negative correlation, at business cycle frequencies, between the net job creation rate of large employers and the level of aggregate unemployment that is much stronger than for small employers. The differential growth rate of employment between initially large and small employers has an unconditional correlation of —0.5 with the unemployment rate, and varies by about 5 percent over the business cycle. We exploit several datasets from the United States, Denmark, and France, both repeated cross sections and job flows with employer longitudinal information, spanning the last four decades and several business cycles. We discuss implications for theories of factor demand. (JEL D22, E23, E32, J23, L25)

Recessions are times of increased uncertainty and volatility at the micro level. This widely documented empirical pattern has been interpreted as the effect of uncertainty shocks, mediated by various frictions, on aggregate economic activity. We explore the hypothesis that the causation runs the opposite way: first moment shocks induce risky behavior, which in turn raises observed cross-sectional dispersion and time series volatility of individual economic outcomes. Specifically, we study the cyclical pattern of the dispersion of price changes, and the resulting changes in sales and employment at the firm-level. We formulate an imperfect information version of the standard model of monopolistic competition. The elasticity of demand differs across products, and firms are not sure about the elasticity of the demand they face, but learn it from their volume of sales. Due to a fixed operation cost, information is valuable to decide whether to exit the market. Idiosyncratic demand shocks impair learning. The model is fully microfounded and can be aggregated to study general equilibrium. Deviations from average prices are costly to the firm in terms of forgone profits, but the response of sale volumes is informative about market power. Bad economic times are the best times to price-experiment, as the opportunity cost of price mistakes is lower and exit looms large. Following a negative aggregate shock to nominal spending, firms at first keep their prices relatively high, in order to learn whether the demand for their product is sufficiently inelastic and resilient to survive, and then change them further by an amount that depends on what they have learned.

In other work (Moscarini and Postel-Vinay, 2008, 2009a), we find a distinct cyclical pattern of the relative performance of large and small businesses in terms of net job creation. Large employers destroy proportionally more jobs during and right after recessions, and create proportionally more jobs late in expansions, relative to small employers. Differential size growth between small and large firms is strongly positively correlated with the unemployment rate. This pattern is observer both in a 1978-2005 census of U.S. employers, the Business Dynamics Statistics, and among listed companies, in Compustat. In this paper, we show that this cyclical pattern of relative performance is also reflected in stock returns. Specifically, we show that the difference in returns between benchmark portfolios of small cap stocks and portfolios of large cap stocks is also positively correlated with the unemployment rate. Financial consultants and fund managers commonly recommend investing in small cap stocks during business cycle recoveries. Our findings, while consistent with that advice, pertain to all phases of the business cycle. We propose an explanation of both facts based on dynamic competition between employers of different sizes and different productivities. The model is a stochastic dynamic version of the job search and wage posting model of Kenneth Burdett and Dale T. Mortensen (1998), which we analyze in detail in Moscarini and Postel-Vinay (2009b). It is a job ladder model, where smaller firms are smaller because they are less productive, offer lower wages, therefore are less attractive to workers and less successful in poaching workers out of competing firms. This lack of competitiveness on the labor market is more of a drawback

This introduces the Symposium on Search Theory and Applications.

We study a winner-take-all R&D race where firms are privately informed about the uncertain arrival rate of the invention. Due to the interdependent-value nature of the problem, the equilibrium displays a strong herding effect that distinguishes our framework from war-of-attrition models. Nonetheless, equilibrium expenditure in R&D is sub-optimal when the planner is sufficiently impatient. Pessimistic firms prematurely exit the race, so that the expected discounted amount of R&D activity is inefficiently low. This result stands in contrast to the overinvestment in research that is typical of winner-take-all R&D races without private information. We conclude that secrecy in R&D inefficiently slows down the pace of innovation.

We study aggregate equilibrium dynamics of a frictional labor market where firms post employment contracts and workers search randomly on and off the job for such contracts, while the economy is hit by aggregate productivity shocks. Our exercise provides the first analysis of aggregate dynamics of a popular class of search wage-posting models with undirected job search.

We provide new evidence that large firms or establishments are more sensitive than small ones to business cycle conditions. Larger employers shed proportionally more jobs in recessions and create more of their new jobs late in expansions, both in gross and net terms. The differential growth rate of employment between large and small firms varies by about 5% over the business cycle. Omitting cyclical indicators may lead to conclude that, on average, these cyclical effects wash out and size does not predict subsequent growth (Gibrat's law). We employ a variety of measures of relative employment growth, employer size and classification by size. We revisit two statistical fallacies, the Regression and Reclassification biases, that can affect our results, and we show empirically that they are quantitatively modest given our focus on relative cyclical behavior. We exploit a variety of (mostly novel) U.S. datasets, both repeated cross-sections and job flows with employer longitudinal information, starting in the mid 1970's and now spanning four business cycles. The pattern that we uncover is robust to different treatments of entry and exit of firms and establishments, and occurs within, not across broad industries, regions and states. Evidence on worker flows suggests that the pattern is driven at least in part by excess layoffs by large employers in and just after recessions, and by excess poaching by large employers late in expansions. We find the same pattern in similar datasets in four other countries, including full longitudinal censuses of employers from Denmark and Brazil. Finally, we sketch a simple firm-ladder model of turnover that can shed light on these facts, and that we analyze in detail in companion papers.