Who Moonlights and Why?: Evidence from the SIPP

Multiple job-holding is a significant characteristic of the labor market, with approximately 6 percent of all employed males reporting a second job in 1993 (Mishel and Bernstein, 1995, p. 226). Moonlighting reflects growing financial stress arising from declining earnings, as well as an increased need for flexibility to combine work and family. Approximately 40 percent of moonlighters report taking the second job due to economic hardship. Additionally, moonlighting is a reflection of the worker's choice to pursue entrepreneurial activities while maintaining the financial stability offered by the primary job. To restate in economic terminology, moonlighting arises from at least two distinct reasons. First, many individuals hold multiple jobs due to some sort of constraint on the primary job that limits that job's earnings capacity. Second, moonlighting may arise because the labor supplied to the two jobs are not perfect substitutes. That is, the wage paid and utility lost from the forgone leisure may not completely reflect the benefits and costs to working. For example, working on the primary job may provide the worker with the credentials to acquire a higher paying second job, such as a university psychologist testifying in a jury trial. Or, working on the second job may provide some satisfaction not received in the same amount or manner from the primary job, such as a comedian who has a "regular" job by day and performs at night. In either example, the costs and benefits of both jobs are more complex than the monetary wages paid and the forgone value of leisure. When faced with such nonpecuniary benefits and costs, optimizing behavior may lead a worker to take two jobs. In contrast to workers who moonlight because they are constrained on their primary jobs (PJ), we expect these kinds of moonlighters to moonlight for longer periods of time because optimizing behavior leads them to supply labor to more than one job, even in the long run. We might also expect to see smaller wage differences between jobs for such workers and the second job (SJ) wage could even be higher than the primary job wage in some situations. Previous research on moonlighting, including Shishko and Rostker (1976), O'Connell (1979) and Krishnan (1990), acknowledges that multiple motives may exist but focuses only on the constraint motive. In related studies, Paxson and Sicherman (1994) explore moonlighting as an alternative avenue for adjusting short-run labor supply, and Abdukadir (1992) examines the possibility that moonlighting is caused by short-term liquidity constraints. Another possible motivation for moonlighting is that certain types of job situations present greater opportunities for tax evasion. Plewes and Stinson (1991) provide survey evidence from the 1989 Current Population Survey of the many distinct reasons for moonlighting reported by workers. The only research in the moonlighting literature that models the joint motives for moonlighting correctly while controlling for the endogeneity of primary job hours are Lilja (1991) and Conway and Kimmel (1994). The latter improves upon Lilja (1991) by specifying a more plausible utility maximizing model and developing a superior instrument for PJ hours. This research examines the characteristics of moonlighters and the length of their moonlighting episodes with the goal of understanding who moonlights and why. The data are for prime-aged men and are drawn from the 1984 Survey of Income and Program Participation (SIPP) panel. The primary advantages of the SIPP are the detailed information provided on up to two jobs (including job start and end dates) and the relatively short length of time (four months) covered by each interview of the survey. Both of these qualities make it possible to identify brief (as well as long) periods of moonlighting, movements into and out of jobs, and the characteristics associated with each job. Because moonlighting may be motivated by short-term financial needs, being able to observe short moonlighting durations is important. We begin by studying the personal and job-related characteristics of moonlighters and how the length of the moonlighting episode varies with these characteristics. We then estimate a duration model with unobserved heterogeneity to identify formally the determinants of moonlighting behavior when multiple motives may exist. Our expectation is that individuals who moonlight because they are constrained on their primary jobs might do so for shorter periods than those who are "job-packaging." Therefore, the hazard rate for workers who moonlight because of primary job constraints should be greater than for those with alternative motives, ceteris paribus. The mixed hazard function will vary as the composition of the sample changes with the duration of the moonlighting episode. By exploring the importance of heterogeneity and the direction of duration dependence of the mixed and structural hazard functions, we gain new insights into the determinants of moonlighting behavior. The descriptive analyses reveal that most moonlighters in our sample work full-time on their primary jobs and 15 to 20 hours a week on lower paying second jobs, and, in spite of those long hours, tend to be poorer than the average worker. Yet, a significant minority earns a higher wage on their second job. Our duration model results suggest that the structural hazard increases over time and there is significant unobserved heterogeneity. Taken together, these results are consistent with the presence of multiple motives for moonlighting, with the constraint motive being the most common.moonlighting, jobs, Kimmel, Conway

Moonlighting Behavior: Theory and Evidence

Two labor supply issues that have received substantial attention are the responsiveness of labor supply to wage changes and the imposition of labor supply constraints. Adjusting hours worked on a second job may be the practical and perhaps only available response to either event yet, most labor supply studies only examine behavior on the primary job. Examining the motives for moonlighting provides evidence on both the wage-responsiveness of labor supply in general and the existence and consequences of labor supply constraints. If, for instance, workers moonlight only when constrained on their primary jobs, then moonlighting itself implies that labor supply constraints exist and so supports the previous literature that incorporates these constraints (e.g. Hamm 1982, 1986). Regardless of the motive for moonlighting, allowing for potential labor supply adjustments on more than one job may very will alter the much-accepted conclusion regarding the inelasticity f male labor supply (for surveys, see Killingsworth 1983 or Pencavel 1986). By ignoring moonlighting behavior, researchers may be eliminating the most significant avenue for short term labor supply adjustments. Our research substantially improves the manner in which moonlighting is examined, and in so doing sheds new light on male labor supply elasticities. Specifically, we devise a theoretical model that permits different reasons for moonlighting and considers moonlighting in tandem with labor supply behavior on the primary job. Estimating both primary and secondary job hours equations using panel data from the SIPP (Survey of Income and Program Participation ) for prime-aged men, we find evidence that the decision to moonlight is quite responsive to wage changes (on both jobs) and arises from at least two distinct motives. Furthermore, properly modeling primary job hours constraints and differences in moonlighting motives reveals that the desired labor supply of prime-aged males is much more wage-elastic than typically assumed. Why do some people choose to moonlight? The predominant view is that it results from a constraint on hours worked on the primary job (Shishko and Rostker (1976), O'Connell (1979) and Krishnan (1990)). Due to workweek restrictions, economic conditions or other institutional factors, the worker is unable to work (or earn) as much as he or she desires on the primary job (PJ), and may thus consider taking a second job. The decision to moonlight hinges on a comparison between the reservation wage and the wage earned on a second job (SJ). The reservation wage and, there fore, the decision to moonlight will depend in part on the number of hours worked on the primary job. A major shortcoming of the aforementioned studies is the inclusion of (exogenous) primary job hours in moonlighting equations estimated for all workers (even non-moonlighters), many of whom may be unconstrained on their primary jobs. Indeed, estimating hours worked on the PJ as a choice variable is the purpose of a great many labor supply studies. To treat is as fixed and exogenous for all workers in inconsistent with basic economic theory and will likely lead to biased parameter estimates. Our econometric model corrects this misspecification and predicts which workers are constrained on their primary jobs. Another explanation for moonlighting behavior is that labor supplied to different jobs may not be perfect substitutes or, put differently, the age paid and utility lost form the foregone leisure may not completely reflect the benefits and costs to working. For example, working on the primary job may provide the worker with the credentials to take on a higher paying second job, such as a university professor who engages in consulting. Or, working on the second job may provide some pleasure (or less displeasure) but pay less than the primary job, such as a musician who has a "regular" job by day and performs at night. In either example, the costs and benefits of both jobs are more complex than the monetary wages paid and the forgone value of leisure. When faced with such nonpecuniary benefits and costs, optimizing behavior may lead a worker to take two jobs. Whereas Shishko and Rostker (1976) and others acknowledge that such a motive may exist, only Lilja (1991) explores it theoretically and empirically. Using Finnish data, the author finds evidence that this second motive better explains male moonlighting behavior that the first, more popular view. We build on Lilja's work by constructing a more consistent theoretical model and by explicitly modeling the behavior on the first job. Our research examines moonlighting behavior recognizing that workers may moonlight because of constraints on their primary jobs or because the two jobs are heterogeneous. We make no a priori assumptions regarding the existence of PJ constraints. We choose the SIPP data for our empirical analysis because it has detailed information on the second job that is superior to that available in other surveys (namely the panel Study of Income Dynamics, National Longitudinal Survey, and Current Population Survey), and it has a short (four month) survey period that permits us to better observe worker movements into and out of jobs. Cross-sectional data likely understate the true degree of moonlighting. In sum, our results help answer the questions of who moonlights and why, as well as provide new evidence of the wage-responsiveness of labor supply on both jobs and the prevalence of labor supply constraints.moonlighting, second, jobs, labor, Conway, Kimmel

What About Mom? The Forgotten Beneficiary of the Medicaid Expansions

This paper contributes to evidence regarding the effectiveness of the Medicaid expansions by focusing on a key beneficiary - the mother - who has previously been overlooked. Using the Natality Detail Files for 1989-96, we estimate the relationship between Medicaid eligibility and maternal health outcomes for several treatment groups and a control group. Potential biases caused by improved reporting are addressed by using a 'straw man' maternal complication not preventable with prenatal care. Our results suggest that increased Medicaid eligibility lead to fewer preventable maternal complications among women most likely to have benefited from the Medicaid expansions.Maternal health; Medicaid; Prenatal care

Shorebird Breeding Biology in Wetlands of the Playa Lakes, Texas, USA

Wetlands in the Playa Lakes Region of Texas are important habitats for North American wintering waterfowl and migrant shorebirds. However, shorebird breeding biology has been overlooked in characterizing the region’s ecological importance. In 1998 and 1999, American Avocet (Recurvirostra americana), Black-necked Stilt ( Himantopus mexicanus ), Killdeer (Charadrius vociferous), and Snowy Plover (C. alexandrinus) breeding ecology were studied in playas, saline lakes, and riparian wetlands in the Playa Lakes Region of Texas. Chronology of nest initiation, clutch sizes, and hatching success for 298 Snowy Plover, 111 American Avocet, 43 Killdeer, and 26 Blacknecked Stilt clutches were measured. All four species nested in saline lakes, American Avocet and Killdeer also nested in playas, and Snowy Plover nested on riparian wetlands. American Avocet had higher hatching success in 1999 (52%) than 1998 (8%), because of more suitable hydrological conditions and lower predation. Hatching success was higher in 1998 than 1999 for Killdeer (1998, 63%; 1999, 21%) and Snowy Plover (1998, 47%; 1999, 33%) due to failures caused by flooding and hail in 1999. In other regions, clutch predation limits shorebird productivity, but hatching success in the Playa Lakes Region appears to be limited by unpredictable precipitation patterns and wetland hydroperiod. As such, breeding shorebird conservation and management should focus upon maintaining wetland hydrological integrity

eHealth and the use of individually tailored information:a systematic review

Tailored messages are those that specifically target individuals following an assessment of their unique characteristics. This systematic review assesses the evidence regarding the effectiveness of tailoring within eHealth interventions aimed at chronic disease management. OVID Medline/Embase databases were searched for randomised control trials, controlled clinical, trials, before -after studies, and time series analyses from inception - May 2014. Objectively measured clinical processes/outcomes were considered. Twenty-two papers were eligible for inclusion: 6/22 used fully tailored messaging and 16/22 used partially tailored messages. Two studies isolated tailoring as the active component. The remainder compared intervention with standard care. In all, 12/16 studies measuring clinical processes and 2/6 studies reporting clinical outcomes showed improvements, regardless of target group. Study quality was low and design did not allow for identification of interventions’ active component. Heterogeneity precluded meta-analysis. This review has demonstrated that there is a lack of evidence to suggest that tailoring within an eHealth context confers benefit over non-tailored eHealth interventions. </jats:p

Nasal Drug Delivery Systems: An Overview

Since ancient times, drugs have been administered via the nasal route for therapeutic and recreational purposes. The interest in, and importance, of the systemic effects of drugs administered through the nasal route, have expanded over recent decades. Intra-nasal administration of drugs offers an interesting alternative for achieving systemic therapeutic effects of drugs that are comparable to the parenteral route, which can be inconvenient at times or oral administration, which can result in unacceptably low drug bioavailability. So, it is important to understand the potential and limitations of various nasal drug delivery systems. Therefore, the aim of this review article is to discuss the various pharmaceutical dosage forms that have the potential to be utilised for local or systemic drug administration. It is intuitively expected that this review will help to understand and further to develop suitable intra-nasal formulations to achieve specific therapeutic objectives

Shorebird Habitat Use and Nest-site Selection in the Playa Lakes Region

Wetlands in the Playa Lakes Region (PLR) provide important habitats for wintering waterfowl, cranes, and both migrant and breeding shorebirds. Playa Lakes Region wetlands experience naturally fluctuating hydroperiods but are exposed to anthropogenic stresses, which are exacerbated during summer and may influence PLR wetland occupancy and selection by breeding shorebirds. We examined wetland-scale habitat use and nest-site selection of the 4 dominant shorebirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], killdeer [Charadrius vociferus], snowy plovers [C. alexandrinus]) nesting in playas, saline lakes, and in both created and riparian wetlands in the PLR of Texas, USA. All 4 species nested in saline lakes. Only avocets and kill deer nested in playas, and snowy plovers nested in riparian wetlands. No nests were found in created wetlands. Wetland habitat changed (P \u3c 0.001) during the breeding season, while water habitats generally decreased. Used (i.e., shorebirds found nesting) wetlands had more (P \u3c 0.05) mudflats than non-used (i.e., shorebirds not found nesting) wetlands, which had more (P \u3c 0.05) dry habitats. Used and non-used wetlands had similar (P \u3e 0.05) amounts of water habitats. Nests were located close to vegetation on bare dry ground and dry ground with vegetation. Because water is ephemeral in PLR wetlands, shorebirds must select—in a somewhat predictive manner upon arrival—wetlands with suitable nest-site and brood-rearing habitat. Although surface water is necessary for nesting, its presence is not adequate for delineating suitable PLR wetland habitat for breeding shorebirds. Our findings that created wetlands cannot compensate for regional wetland losses in habitat or function highlights the need for conservation of natural PLR wetlands

Feeding of anchovy Engraulis encrasicolus larvae in the northwestern Adriatic Sea in response to changing hydrobiological conditions

Results from depth integrated and vertically stratified plankton sampling in the northwestern Adriatic Sea were used for comparison of gut contents of larvae of European anchovy Engraulis encrasicolus with composition and concentration of potential prey in the plankton. Sampling was carried out over a grid of stations both before and after a period of increased wind mixing to investigate changes in food availability and larval feeding success. All larvae had empty guts soon after dusk, indicating daytime feeding and rapid gut clearance. With increasing larval length there was a greater percentage of specimens with empty guts, despite suitable food being available in the plankton for these larger larvae; this suggests differential gut evacuation during sampling-possibly related to the degree of gut development. Larval diet was principally the various developmental stages of copepods, especially calanoid and cyclopoid nauplii, which were preferentially selected by larvae, whereas selection was against harpacticoid nauplii. Lamellibranch larvae and Peridinium were generally abundant in the plankton, but were only present in the gut contents in any number when the preferred dietary organisms were present in the plankton at low concentrations. The number of food organisms in the gut contents increased with concentration of the preferred food organisms in the plankton up to a limit of similar to 50 organisms/l. Within the upper 18 m of the water column, there was a reduction in the proportion of larvae with food in their guts with increasing depth, irrespective of the vertical profile of food concentration. Following a period of wind mixing the composition of the plankton changed. This was reflected in the diet of anchovy larvae, which altered in parallel. There was also an overall 41% decrease in concentration of the preferred food particles of larvae in the plankton following the period of wind mixing, but larvae were still able to maintain their food intake. These results show that anchovy larvae can successfully adapt their diet to a changing prey field and suggest that in the conditions observed in the northern Adriatic, quite radical changes in the feeding environment were probably insufficient to affect overall larval mortality

VLBI Observations of NGC6240: resolving the double nuclei and radio supernovae

The European VLBI Network (EVN) has been used at two epochs in 2003 and 2009 to obtain multi-frequency high-resolution images of the merger galaxy NGC6240 in order to study the radio properties of all compact high-brightness components in the galaxy. Our observations at milli-arcsecond resolution detected the northern and southern nuclei and two radio components, which we interpret as long-lived luminous supernovae associated with the circum-nuclear starburst activity at the southern nucleus. The new VLBI data support the presence of an active galactic nucleus (AGN) together with starburst activity at the southern nucleus and provides some evidence for an AGN at the northern nucleus. The two nuclei both display an inverted spectrum at lower GHz frequencies. The spectrum of the southern nucleus indicates thermal free-free absorption on parsec scales, consistent with the presence of an AGN.Comment: 19 pages, 6 figures, accepted for publication in the Astronomical Journa

Breeding Biology of an Interior Least Tern (Sterna Antillarum Athalassos) Colony in Childress County of North Texas

This study documented nest success, nest initiation chronology and nest site selection for interior least terns (Sterna antillarum athalassos) along the Prairie Dog Town Fork of the Red River in Childress County, Texas during 1998. Terns experienced a 65% nest success rate (Mayfield estimate 71 %) and clutch sizes ranged from 1 3 eggs (x = 2.25) for 20 nests. Seventy percent of all nests were initiated during the first 20 days of June, which coincided with the highest number of adult terns observed on the study site. All nests were found on gravel/sand bars in the river basin; 25% were placed on gravel and 75% were placed on sand. Sixty-five percent of tern nests were located within 15 cm of driftwood and/or rocks, but nests were not more frequently associated with objects than random sites (P \u3e 0.05). Nests were generally \u3e 10 m from vegetative cover and 200 m from surface water. However, habitat variables (i.e., distances to upland, mudflat, water and vegetative cover) did not vary (P \u3e 0.05) between nests and random sites nor between successful and nonsuccessful nests. This colony of interior least terns was last documented in the mid-1980s and evidently has some degree of stability. Conservation efforts should focus on protecting, restoring and enhancing riparian wetland habitats in the High and Rolling Plains of Texas for this endangered species