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101.
Over the last few years, marijuana has become legally available for recreational use to roughly a quarter of Americans. Policy makers have long expressed concerns about the substantial external costs of alcohol, and similar costs could come with the liberalization of marijuana policy. Indeed, the fraction of fatal accidents in which at least one driver tested positive for tetrahydrocannabinol has increased nationwide by an average of 10% from 2013 to 2016. For Colorado and Washington, both of which legalized marijuana in 2014, these increases were 92% and 28%, respectively. However, identifying a causal effect is difficult due to the presence of significant confounding factors. We test for a causal effect of marijuana legalization on traffic fatalities in Colorado and Washington with a synthetic control approach using records on fatal traffic accidents from 2000 to 2016. We find the synthetic control groups saw similar changes in marijuana-related, alcohol-related, and overall traffic fatality rates despite not legalizing recreational marijuana. (JEL K42, I12, I18) 相似文献
102.
Urban Ecosystems - Urbanization may negatively affect forest obligate bat species. We compared the roosting behavior of federally endangered Indiana bats (Myotis sodalis) in a fragmented site,... 相似文献
103.
The good government models of the 1990s realized a focus that included reinventing, reengineer-ing, rethinking, quality, empowerment, and devolution of the organization. These organizational reform ideologies sought to increase involvement, improve productivity, manage performance, and drive results. One essential key that has been disregarded in these government models is the involvement of community in the decision-making process. This paper points to the importance of involving and empowering citizens in the decision-making process, particularly in regard to community justice based on the notion of restorative justice system. Community justice, a modern day reform movement with international proportions, is based on the principles of empowering community, repairing harm caused by a crime or disturbance, and reducing risk to the community. 相似文献
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105.
A set S of vertices of a graph G is a total outer-connected dominating set if every vertex in V(G) is adjacent to some vertex in S and the subgraph induced by V?S is connected. The total outer-connected domination number γ toc (G) is the minimum size of such a set. We give some properties and bounds for γ toc in general graphs and in trees. For graphs of order n, diameter 2 and minimum degree at least 3, we show that $\gamma_{toc}(G)\le \frac{2n-2}{3}$ and we determine the extremal graphs. 相似文献
106.
Raul O. Chao Kenneth C. Lichtendahl Yael Grushka‐Cockayne 《Production and Operations Management》2014,23(8):1286-1298
Many large organizations use a stage‐gate process to manage new product development projects. In a typical stage‐gate process project managers learn about potential ideas from research and exert effort in development while senior executives make intervening go/no‐go decisions. This decentralized decision making results in an agency problem because the idea quality in early stages is unknown to the executive and the project manager must exert unobservable development effort in later stages. In light of these challenges, how should the firm structure incentives to ensure that project managers reveal relevant information and invest the appropriate effort to create value? In this study, we develop a model of adverse selection in research and moral hazard in development with a go/no‐go decision at the intervening gate. Our results show that the principal's uncertainty regarding early‐stage idea quality—a term we refer to as idea risk—alters the effect of late‐stage development risk. The presence of idea risk can alter the incentives offered to the agent and may lead the principal to reject projects that otherwise seem favorable in terms of positive net present value. A simulation of early‐stage ideas, found through search on a complex landscape, shows that the firm can mitigate the negative effects of idea risk by encouraging breadth of search and high tolerance for failure. 相似文献
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108.
This paper advances knowledge regarding how fathers and mothers perceive and experience flexible working opportunities. It does this through applying the theoretical concept ‘belonging’ to ‘Parsonian’ classifications of parenting and work. In so doing it makes transparent the misconceptions and inequities which exist among parents and their organizational environments. Focusing initially on a qualitative study of fathers’ experience of working flexibly, the paper shows how fathers felt marginalized from the possibilities of flexible work due to line managers’ assumptions that men belonged to an ‘instrumental’ economic provider group. The paper contributes a new angle to debate by articulating how fathers perceived employed mothers as belonging to an ‘expressive’ child‐oriented group, with privileged access to flexibility. However, drawing upon a study of maternity and flexible work we query fathers’ assumptions that flexibility was easily available to mothers, suggesting that fathers’ perceptions of maternal privilege were misconceived. While mothers were categorized as belonging within an ‘expressive’ group associated with childcare, they were nevertheless discouraged from accessing flexibility. Inequities between women and men (with regard to flexibility) thus appeared to be less significant than fathers supposed. 相似文献
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110.
Risk Estimation and Value-of-Information Analysis for Three Proposed Genetic Screening Programs for Chronic Beryllium Disease Prevention 总被引:1,自引:0,他引:1
Scott M. Bartell Rafael A. Ponce Timothy K. Takaro Richard O. Zerbe Gilbert S. Omenn & Elaine M. Faustman 《Risk analysis》2000,20(1):87-100
Genetic differences (polymorphisms) among members of a population are thought to influence susceptibility to various environmental exposures. In practice, however, this information is rarely incorporated into quantitative risk assessment and risk management. We describe an analytic framework for predicting the risk reduction and value-of-information (VOI) resulting from specific risk management applications of genetic biomarkers, and we apply the framework to the example of occupational chronic beryllium disease (CBD), an immune-mediated pulmonary granulomatous disease. One described Human Leukocyte Antigen gene variant, HLA-DP beta 1*0201, contains a substitution of glutamate for lysine at position 69 that appears to have high sensitivity (approximately 94%) but low specificity (approximately 70%) with respect to CBD among individuals occupationally exposed to respirable beryllium. The expected postintervention CBD prevalence rates for using the genetic variant (1) as a required job placement screen, (2) as a medical screen for semiannual in place of annual lymphocyte proliferation testing, or (3) as a voluntary job placement screen are 0.08%, 0.8%, and 0.6%, respectively, in a hypothetical cohort with 1% baseline CBD prevalence. VOI analysis is used to examine the reduction in total social cost, calculated as the net value of disease reduction and financial expenditures, expected for proposed CBD intervention programs based on the genetic susceptibility test. For the example cohort, the expected net VOI per beryllium worker for genetically based testing and intervention is $13,000, $1,800, and $5,100, respectively, based on a health valuation of $1.45 million per CBD case avoided. VOI results for alternative CBD evaluations are also presented. Despite large parameter uncertainty, probabilistic analysis predicts generally positive utility for each of the three evaluated programs when avoidance of a CBD case is valued at $1 million or higher. Although the utility of a proposed risk management program may be evaluated solely in terms of risk reduction and financial costs, decisions about genetic testing and program implementation must also consider serious social, legal, and ethical factors. 相似文献