2,540 research outputs found
The Flow Approach to Labor Markets: New Data Sources and Micro-Macro Links
New data sources and products developed by the Bureau of Labor Statistics and the Bureau of the Census highlight the fluid character of U.S. labor markets. Private-sector job creation and destruction rates average nearly 8% of employment per quarter. Worker flows in the form of hires and separations are more than twice as large. The data also underscore the lumpy nature of micro-level employment adjustments. More than two-thirds of job destruction occurs at establishments that shrink by more than 10% within the quarter, and more than one-fifth occurs at those that shut down. Our study also uncovers highly nonlinear relationships of worker flows to employment growth and job flows at the micro level. These micro relations interact with movements over time in the cross-sectional density of establishment growth rates to produce recurring cyclical patterns in aggregate labor market flows. Cyclical movements in the layoffs-separation ratio, for example, and the propensity of separated workers to become unemployed reflect distinct micro relations for quits and layoffs. A dominant role for the job-finding rate in accounting for unemployment movements in mild downturns and a bigger role for the job-loss rate in severe downturns reflect distinct micro relations for hires and layoffs.
The Establishment-Level Behavior of Vacancies and Hiring
This paper is the first to study vacancies, hires, and vacancy yields at the establishment level in the Job Openings and Labor Turnover Survey, a large sample of U.S. employers. To interpret the data, we develop a simple model that identifies the flow of new vacancies and the job-filling rate for vacant positions. The fill rate moves counter to aggregate employment but rises steeply with employer growth rates in the cross section. It falls with employer size, rises with worker turnover rates, and varies by a factor of four across major industry groups. We also develop evidence that the employer-level hiring technology exhibits mild increasing returns in vacancies, and that employers rely heavily on other instruments, in addition to vacancies, as they vary hires. Building from our evidence and a generalized matching function, we construct a new index of recruiting intensity (per vacancy). Recruiting intensity partly explains the recent breakdown in the standard matching function, delivers a better-fitting empirical Beveridge Curve, and accounts for a large share of fluctuations in aggregate hires. Our evidence and analysis provide useful inputs for assessing, developing and calibrating theoretical models of search, matching and hiring in the labor market.
The establishment-level behavior of vacancies and hiring
The authors study vacancies, hires, and vacancy yields (success rate in generating hires) in the Job Openings and Labor Turnover Survey, a large representative sample of U.S. employers. The authors also develop a simple framework that identifies the monthly flow of new vacancies and the job-filling rate for vacant positions, the employer counterpart to the job-finding rate for unemployed workers. The job-filling rate moves counter to employment at the aggregate level but rises steeply with employer growth rates in the cross section. It falls with employer size, rises with the worker turnover rate, and varies by a factor of four across major industry groups. The authors' analysis also indicates that more than 1 in 6 hires occur without benefit of a vacancy, as defined by JOLTS. These findings provide useful inputs for assessing, developing, and calibrating theoretical models of search, matching, and hiring in the labor market.Employment ; Labor market
Recruiting Intensity during and after the Great Recession: National and Industry Evidence
We measure job-filling rates and recruiting intensity per vacancy at the national and industry levels from January 2001 to September 2011 using data from the Job Openings and Labor Turnover Survey. Construction makes up less than 5 percent of employment but accounts for more than 40 percent of the large swings in the job-filling rate during and after the Great Recession. Leisure & Hospitality accounts for nearly a quarter of the large drop in recruiting intensity during the Great Recession. We show that industry-level movements in job-filling rates and recruiting intensity are at odds with the implications of the standard matching function in labor search theory but consistent with a generalized function that incorporates an important role for recruiting intensity per vacancy.
New Results on Subtractive Magic Graphs
For any edge xy in a directed graph, the subtractive edge-weight is the sum of the label of xy and the label of y minus the label of x. Similarly, for any vertex z in a directed graph, the subtractive vertex-weight of z is the sum of the label of z and all edges directed into z and all the labels of edges that are directed away from z. A subtractive magic graph has every subtractive edge and vertex weight equal to some constant k. In this paper, we will discuss variations of subtractive magic labelings on directed graphs
Computed tomography measures of nutrition in patients with end-stage liver disease provide a novel approach to characterize deficits
Aim
Patients with cirrhosis and end-stage liver disease (ESLD) develop severe nutrition deficits that impact on morbidity and mortality. Laboratory measures of nutrition fail to fully assess clinical deficits in muscle mass and fat stores. This study employs computed tomography imaging to assess muscle mass and subcutaneous and visceral fat stores in patients with ESLD.
Methods
This 1:1 case-control study design compares ESLD patients with healthy controls. Study patients were selected from a database of ESLD patients using a stratified method to assure a representative sample based on age, body mass index (BMI), gender, and model for end-stage liver disease score (MELD). Control patients were trauma patients with a low injury severity score (<10) who had a CT scan during evaluation. Cases and controls were matched for age +/- 5 years, gender, and BMI +/- 2.
Results
There were 90 subjects and 90 controls. ESLD patients had lower albumin levels (p<0.001), but similar total protein levels (p=0.72). ESLD patients had a deficit in muscle mass (-19%, p<0.001) and visceral fat (-13%, p<0.001), but similar subcutaneous fat (-1%, p=0.35). ESLD patients at highest risk for sarcopenia included those over age 60, BMI< 25.0, and female gender. We found degree of sarcopenia to be independent of MELD score.
Conclusions
These results support previous research demonstrating substantial nutrition deficits in ESLD patients that are not adequately measured by laboratory testing. Patients with ESLD have significant deficits of muscle and visceral fat stores, but a similar amount of subcutaneous fat
Labor Market Flows in the Cross Section and Over Time
Many theoretical models of labor market search imply a tight link between worker flows (hires and separations) and job gains and losses at the employer level. Partly motivated by these theories, we exploit establishment-level data from U.S. sources to study the relationship between worker flows and job flows in the cross section and over time. We document strong, highly nonlinear relationships of hiring, quit and layoff rates to employer growth in the cross section. Simple statistical models that capture these cross-sectional relationships greatly improve our ability to account for fluctuations in aggregate worker flows. We also evaluate how well various theoretical models and views fit the patterns in the data. Aggregate fluctuations in layoffs are well captured by micro specifications that impose a tight cross-sectional link between worker flows and job flows. Aggregate fluctuations in quits are not. Instead, quit rates rise and fall with booms and recessions across the distribution of establishment growth rates, but more so at shrinking employers. Finally, we use our preferred statistical models – in combination with data on the cross-sectional distribution of establishment growth rates – to construct synthetic JOLTS-type measures of hires, separations, quits and layoffs back to 1990.
Optimum Magnetometer Transect Spacing to Locate Legacy Oil and Gas Wells: Preliminary Results
The purpose of this project was to examine the optimum transect spacing to locate legacy oil and gas wells using an Overhauser magnetometer. Widely known to be a potential environmental hazard, legacy oil and gas wells may act as a conduit for methane and/or deeper subsurface fluids (naturally occurring brines, injected waste fluids, or injected CO2) to the surface or shallow subsurface. Many plugged wells have all surface equipment removed leaving no visible trace at the surface and thus making the environmental assessment of these wells difficult. Using a magnetometer along a set of predefined transects, magnetic anomalies from the metal casing can be detected. In order to assess large numbers of wells, understanding the typical anomaly size is critical to maximize the transect spacing and therefore minimize magnetometer field work time. Here we briefly review the wide range of transect spacings reported in the literature and show the results of five wells with an initial survey grid at two meter spacing. Although there is significant variation in the anomaly size (X, Y, and Z), transect spacing of 20 m was sufficient to identify all buried wells using the method described herein. The anomalies associated with four of the wells ranged from approximately 1000-4000 nanoteslas (nT), while one well anomaly exhibited more than 10,000 nT above background
FABP7: a glial integrator of sleep, circadian rhythms, plasticity, and metabolic function
Sleep and circadian rhythms are observed broadly throughout animal phyla and influence neural plasticity and cognitive function. However, the few phylogenetically conserved cellular and molecular pathways that are implicated in these processes are largely focused on neuronal cells. Research on these topics has traditionally segregated sleep homeostatic behavior from circadian rest-activity rhythms. Here we posit an alternative perspective, whereby mechanisms underlying the integration of sleep and circadian rhythms that affect behavioral state, plasticity, and cognition reside within glial cells. The brain-type fatty acid binding protein, FABP7, is part of a larger family of lipid chaperone proteins that regulate the subcellular trafficking of fatty acids for a wide range of cellular functions, including gene expression, growth, survival, inflammation, and metabolism. FABP7 is enriched in glial cells of the central nervous system and has been shown to be a clock-controlled gene implicated in sleep/wake regulation and cognitive processing. FABP7 is known to affect gene transcription, cellular outgrowth, and its subcellular localization in the fine perisynaptic astrocytic processes (PAPs) varies based on time-of-day. Future studies determining the effects of FABP7 on behavioral state- and circadian-dependent plasticity and cognitive processes, in addition to functional consequences on cellular and molecular mechanisms related to neural-glial interactions, lipid storage, and blood brain barrier integrity will be important for our knowledge of basic sleep function. Given the comorbidity of sleep disturbance with neurological disorders, these studies will also be important for our understanding of the etiology and pathophysiology of how these diseases affect or are affected by sleep
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