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A study of the location of three classifications of high-tech industries in rural areas was undertaken using ordinary least squares, Tobit, and a two-step estimation procedure suggested by Heckman (1976). The results indicate that the location decision for high tech firms is influenced primarily by the county population, adjacency to an SMSA, and the expenditures on public infrastructure (exclusive of education expenditures). However, location near interstate highways was generally not a significant factor. Results were similar between branch and unit (single ownership) plants. Some differences in signs of orders of magnitude occurred among the estimation procedures. Making a choice between Tobit and Heckman approaches depends upon the goal of the research.  相似文献   
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Alewives (Alosa pseudoharengus), the major prey fish for Lake Ontario, contain thiaminase. They are associated with development of a thiamine deficiency in salmonines which greatly increases the potential for developing an early mortality syndrome (EMS). To assess the possible effects of thiamine deficiency on salmonine reproduction we measured egg thiamine concentrations for five species of Lake Ontario salmonines. From this we estimated the proportion of families susceptible to EMS based on whether they were below the ED20, the egg thiamine concentration associated with 20% mortality due to EMS. The ED20s were 1.52, 2.63, and 2.99 nmol/g egg for Chinook salmon (Oncorhynchus tshawytscha), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch), respectively. Based on the proportion of fish having egg thiamine concentrations falling below the ED20, the risk of developing EMS in Lake Ontario was highest for lake trout, followed by coho (O. kisutch), and Chinook salmon, with the least risk for rainbow trout (O. mykiss). For lake trout from western Lake Ontario, mean egg thiamine concentration showed significant annual variability during 1994 to 2003, when the proportion of lake trout at risk of developing EMS based on ED20 ranged between 77 and 100%. Variation in the annual mean egg thiamine concentration for western Lake Ontario lake trout was positively related (p < 0.001, r2 = 0.94) with indices of annual adult alewife biomass. While suggesting the possible involvement of density-dependent changes in alewives, the changes are small relative to egg thiamine concentrations when alewife are not part of the diet and are of insufficient magnitude to allow for natural reproduction by lake trout.  相似文献   
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Between 1998 and 2002, surface water samples were collected from several sites in the Don River and Humber River watersheds, both tributaries to Lake Ontario, and analyzed for a variety of pesticides, including those used for urban lawn care. Analyses included 152 pesticide active ingredients and eight metabolites. Samples were collected during base flow periods (i.e., dry events) and rainfall events (i.e., wet events). The objectives of the study were to determine which pesticides were detectable, whether there was a difference in the detection frequency between the two watersheds and between upstream and downstream in each river, and whether precipitation influenced the frequency of detection. Eleven pesticides and one metabolite were detected in surface waters of the Don and Humber rivers or their tributaries, with approximately 72% of samples containing at least one pesticide attributable to lawn care use. The pesticides and pesticide metabolite detected in this study included 2,4-D, atrazine, bromacil, carbofuran, chlorpyrifos, cypermethrin, diazinon, dicamba, MECOPROP, metolachlor, metribuzin, and an atrazine metabolite (des-ethyl atrazine). Four pesticides exceeded federal or provincial water quality guidelines/objectives. Diazinon exceeded the provincial water quality objective in 28% of the samples taken. For the three other pesticides (atrazine, carbofuran and chlorpyrifos) exceedance of a water quality criteria occurred in less than 1% of the samples.  相似文献   
27.
Diversification Categories in Investment Real Estate   总被引:3,自引:0,他引:3  
This paper continues previous work evaluating the benefits of diversification and analyzes the various dimensions within the commercial real estate opportunity set. The database is large and extends through the 1982 downturn in property values. Due to the low levels of systematic risk, current distinctions by region and property type make little sense in a world of costly diversification. More exacting categories combining property type, SMSA growth rate and lease maturity offer promise for more efficient diversification within the real estate portfolio.  相似文献   
28.
We argue that firms with interdependent worker productivity, team production, have a higher cost of absence and, as a consequence, spend additional resources on monitoring absence. As a result, firms with team production should have lower absence rates. We estimate the determinants of absence for blue‐collar workers using a sample of German manufacturing establishments. Workplace teams are used as a proxy for team production. The estimates reveal that firms with teams have lower absence rates, as do smaller establishments. The size effect, however, is unique to establishments with teams, which fits prior theoretical work that has not been previously tested.  相似文献   
29.
Various claims have been made about the causes of the Asian crisis and its spread. Here, we use data on the behaviour of capital flows during the crisis to test the strong forms of four such hypotheses, that portfolio investors and hedge funds played a dominant role in initiating and/or spreading the crisis; that moral hazard kept efficient markets from predicting the crisis; and, finally, the common lender hypothesis of Kaminsky and Reinhart. In the process we also test implications of the Calvo-Mendoza model of rational investor ignorance. All are falsified as monocausal explanations. For example, portfolio investments that could not have been subject to substantial moral hazard continued to flow into Asia until very shortly before the crisis. Likewise, banks were a much larger source of capital outflows during the crisis than were portfolio investors. While falsified in their strongest forms, several of these hypotheses in less strong forms should play a role in a more nuanced analysis. It is necessary to move past simple single-factor approaches in order to produce a more complete, synthetic explanation of this episode.  相似文献   
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The primary purpose of this paper was to empirically explore some of the reasons that logistics has become more important, or salient, in comparison to other functions within the firm. A survey of 296 managers across multiple industries in the U.S. found logistics becomes more important within the firm when the industry increases in uncertainty, when there is an emphasis on time‐based competition, when there is greater adoption of information technology, and when there is an emphasis on cross‐functional integration.  相似文献   
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