The lay system in commercial fisheries: Origin and implications

In most commercial fisheries, the crew is remunerated via some form of the lay system. Under the lay system, the crew is paid with a share of revenues or a share of revenues less costs. Naturally, the presence and the functioning of the lay system are well known and accepted as one of fishery's important institutions. Compared with share contracts in agriculture, however, the lay in fisheries has garnered relatively little research. This article has two goals. First, we provide an explanation for the existence of the lay system as an incentive mechanism to alleviate a potential team agency problem. This explanation of the lay system explains anomalies, such as the presence of wages in some fisheries, that are odds with the theory of pure risk sharing. Second we show the implications of the lay system for econometric modeling of fisheries and for understanding firm behavior. In general we conclude that models that fail to account explicitly for the incentive properties of shares are likely to provide poor representations of fishing firm behavior. The thrust of the paper is that the formation and working of the lay system are a fundamental force in fisheries influencing firm behavior and research results in a way that has been largely ignored.     

Concentrations of particulate matter emitted from large cattle feedlots in Kansas

Particulate matter (PM) emitted from cattle feedlots are thought to affect air quality in rural communities, yet little is known about factors controlling their emissions. The concentrations of PM (i.e., PM2.5, PM10, and total suspended particulates or TSP) upwind and downwind at two large cattle feedlots (KS1, KS2) in Kansas were measured with gravimetric samplers from May 2006 to October 2009 (at KS1) and from September 2007 to April 2008 (at KS2). The mean downwind and net (i.e., downwind - upwind) mass concentrations of PM2.5, PM10, and TSP varied seasonally, indicating the need for multiple-day, seasonal sampling. The downwind and net concentrations were closely related to the moisture content of the pen surface. The PM2.5/PM10 and PM2.5/TSP ratios at the downwind sampling location were also related to the moisture content of the pen surface, humidity, and temperature. Measurement of the particle size distribution downwind of the feedlot with a cascade impactor showed geometric mean diameter ranging from 7 to 18 microm, indicating that particles that were emitted from the feedlots were generally large in size.     

Determination of vapor pressure-temperature relationships of current–use pesticides and transformation products

Sub-cooled liquid vapor pressures (P_L ⁰) of current–use organochlorine and organophosphate pesticides (chlorothalonil, chlorpyrifos methyl, diazinon, fipronil) and selected transformation products (chlorpyrifos oxon, heptachlor epoxide, oxychlordane, 3,5,6-trichloro-2-pyridinol) were determined at multiple temperatures using the gas chromatography retention time technique. Results were utilized to determine vapor pressure-temperature relationships and to calculate enthalpies of vaporization (ΔH_vap). While results for chlorothalonil and diazinon were comparable with published values, the measured value for fipronil (1.82 × 10^{? 6} Pa) is almost an order of magnitude higher than the reported literature value (3.7 × 10^{? 7} Pa). The availability of vapor pressure temperature relationships for these chemicals will aid in pesticide risk assessment development and improve the effectiveness of mitigation and remediation efforts.     

Biodegradation testing of radioactive waste forms

Biodegradation tests were conducted on solidified waste forms containing ion exchange resins contaminated with high levels of radioactive nuclides. These tests were part of a program to test waste forms in accordance with the U.S. NRC Branch Technical Position on Waste Forms. Small waste forms were manufactured using two different solidification agents, Portland Type I–II cement and vinyl ester-styrene (VES). Ion exchange material was taken from a filter system which had been used to remove radionuclides from highly contaminated water. As specified by NRC, the waste forms were evaluated for their resistance to biological degradation using the G21 and G22 procedures of the American Society for Testing Materials (ASTM). Results showed that microbial growth can be supported by the VES waste forms. The particular organisms used in the tests did not grow in the presence of the cement waste forms. It is also shown that the ASTM tests specified in the Technical Position are not suitable for the use intended. A different testing methodology is recommended which would provide direct verification of waste form integrity.Work supported by the U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, under DOE Contract No. DE-AC07-761D01570.This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. The views expressed in this report are not necessarily those of the U.S. Nuclear Regulatory Commission.     

Amniotic fluid levels of human chorionic gonadotropin and its alpha and beta subunits in second-trimester chromosomally abnormal pregnancies

Amniotic fluid from 135 pregnancies was assayed for human chorionic gonadotropin (hCG) and its free alpha (ahCG) and free beta (bhCG) subunits. Forty-six chromosomally abnormal pregnancies between 14 and 20 weeks' gestation were matched with 89 chromosomally normal samples. Compared with controls, trisomy 21 pregnancies exhibited significantly elevated levels of all three peptides, whereas trisomy 18 gestations gave rise only to significant elevation of ahCG. Female fetuses in both the trisomy 21 and trisomy 18 pregnancies provided significantly elevated levels of hCG and bhCG compared to their male counterparts. On converting the values to multiples of the median, it was determined that 6 of 7 trisomy 18 samples had abnormally elevated alpha/beta ratios, as did 6 of 21 Down's syndrome pregnancies. Further, 11 of 21 trisomy 21 gestations had abnormal amniotic fluid hCG levels. Using only ahCG, bhCG and their ratio, a 61 per cent sensitivity was found for these trisomies, with a 96 per cent specificity.     

Simultaneous estimation of jointly dependent recreation participation function

The purpose of this paper is to develop and estimate a simultaneous model of recreation participation. The logic of the model is that participation in one activity (for example, boating) is influenced by and influences participation in other activities (for example, fishing). For the empirical part of our paper we have used the simultaneous logit model developed by P. Schmidt and R. P. Strauss (Econometrics43, 745–755, 1975). For the application, we have applied the simultaneous logit model to participation in summer recreational activities in Rhode Island. Our results show that simultaneous equation models tend to forecast better, but that the specification bias from excluding the endogenous variables tends to be small.     

Estimating net benefits of recreation under conditions of excess demand

The public provision of outdoor recreation necessitates the development of nonmarket measures of the value of resources in recreational use. Such values can be used as surrogates for market values in the decision-making process. Another aspect of recreation as a publicly provided good is the absence of a mechanism to eliminate automatically excess demand. The absence of such a mechanism has resulted in conditions of excess demand at many recreation sites.This paper deduces the implications of excess demand for the travel cost method of benefit estimation. We show that when excess demand results in rationing at a particular site, the travel cost method will underestimate the true benefits of the site. The results are important because they help identify the direction of bias of one measure of the benefits from the use of a natural resource.     

Atmospheric deposition of pesticides to an agricultural watershed of the Chesapeake Bay

The Choptank River watershed, located on the Delmarva Peninsula of the Chesapeake Bay, is dominated by agricultural land use, which makes it vulnerable to runoff and atmospheric deposition of pesticides. Agricultural and wildlife areas are in close proximity and off-site losses of pesticides may contribute to toxic effects on sensitive species of plants and animals. High-volume air samples (n = 31) and event-based rain samples (n = 71) were collected from a single location in the watershed representing regional background conditions. Surface water samples were collected from eight stations in the tidal portion of the river on five occasions during 2000. Chlorothalonil, metolachlor, atrazine, simazine, endosulfan, and chlorpyrifos were frequently detected in the air and rain, with maximal concentrations during the period when local or regional crops were planted. The wet deposition load to the watershed was estimated at 150 +/- 16, 61 +/- 7, and 51 +/- 6 kg yr(-1) for chlorothalonil, metolachlor, and atrazine, respectively. The high wet deposition load compared with the estimated annual usage for chlorothalonil (13%) and endosulfan (14-90%) suggests an atmospheric source from outside the watershed. Net air-water gas exchange fluxes for metolachlor varied from -44 +/- 19 to 9.3 +/- 4.1 ng m(-2) d(-1) with negative values indicating net deposition. Wet deposition accounted for 3 to 20% of the total metolachlor mass in the Choptank River and was a more important source to the river than gas exchange. Estimates of herbicide flux presented here are probably a low estimate and actual rates may be significantly higher in areas closer to pesticide application.