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There has been tremendous growth in the field of prevention science over the past two decades. The defining features of contemporary prevention science are high quality empirical research using rigorous and well-established scientific methods, careful hyphothesis testing, and the systematic accumulation of knowledge. One area where substantial progress has been made is in our understanding of the etiology and prevention of tobacoo, alcohol, and illicit drug abuse. In this paper, we review the growth in prevention as a scientific enterprise, discuss advances in drug abuse prevention research, and review the effectiveness of one approach to the problem of adolescent drug abuse, the Life Skills Traning (LST) program, and the methodological strengths of the LST evaluation research. In addition, we provide a response to criticism regarding two types of data analysis in evaluation research, and show that these analyses can help address a number of important research questions with implications for theory and practice. First, the analysis of high fidelity subsamples can address research questions about the importance of program implementation fidelity; and second, composite measures of concurrent tobacco, alcohol, and marijuana use (i.e., polydrug use) are useful in testing research questions about program effects on more serious levels of drug involvement. With an increasing number of ramdomized controlled trials underway, the field of prevention science is contributing to a new generation of evidence-based approaches and policies that, if widely utilized, offer the potential of reducing the mortality and morbidity associated with a number of major health and social problems.  相似文献   
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Objectives

This study examines the effectiveness of foot patrol in violent micro-places. A large urban police department deployed foot patrol in micro-places (hot spots) for a period of 90 days for two shifts each day. Our objective is to determine whether this activity impacted violent crime in these hot spots and whether spatial displacement of crime occurred.

Methods

Eight eligible foot beat locations were set by examining crime rates for previous years in order to identify micro-places of high criminal activity. We employed a quasi-experimental design comparing the four treatment to the four control areas, estimating panel-specific autoregressive models for 30 weeks prior to and 40 weeks after the treatment.

Results

Time series models revealed statistically significant reductions in violent crime in the micro-places receiving foot patrol treatment, while no such reductions were observed in the control areas. The deterrent effect, however, was short and dissipated quickly. Control areas did not experience any crime prevention benefit during this time period. No evidence of crime displacement to spatially contiguous areas was detected.

Conclusions

This contributes to the growing body of knowledge that focused police strategies within hot spots impact violent crime. Specifically, the implementation of foot patrol in high crime hot spots led to measurable reductions in aggravated assaults and robberies, without displacing crime to contiguous areas.
  相似文献   
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Ahmed  Sultan  Greene  Kenneth V. 《Public Choice》2000,105(3-4):207-230
This paper attempts to test the power of the median model againstthe respective strength of other alternate models based onredistributive, political-institutional and interest group theoriesin explaining the demand for public spending in New York statecounties during 1990, 1980 and 1970. To execute the comparison ofthe performance of median voter model with that of each of thenonmedian voter ones, various nonnested tests such as J and JAtests, N-tilde, W and encompassing tests have been employed.Results of the study show that although the median voter model hasa marginal edge over the rival models based on the alternativetheories, it may not be relied upon solely when many otherinstitutional, redistributive and interest group factors are alsorelevant for explaining public spending. The results of this studydiffer from those in Congleton and Bennett (1995). We do not findthat interest group models are substantially weaker than the medianvoter model.  相似文献   
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Abstract. Duverger's propositions concerning the psychological and mechanical consequences of electoral rules have previously been examined mainly through the lens of district magnitude, comparing the properties of single–member district plurality elections with those of multimember proportional representation elections. The empirical consequences of multimember plurality (MMP) rules, on the other hand, have received scant attention. Theory suggests that the effect of district magnitude on the number and concentration of parties will differ with regard to whether the allocation rules are plurality–based or proportional. I test this theory by drawing on a uniquely large–sample dataset where district magnitude and electoral formula vary but the basic universe of political parties is held constant, applying regression analysis to data from several thousand Hungarian local bodies elected in 1994 consisting of municipal councils, county councils, and mayors. The results indicate that omitting the variable of electoral formula has the potential to cause significant bias in estimates of Duvergerian consequences of district magnitude. In addition, the analysis of multi–member plurality elections from the local election dataset reveals counter–intuitively that candidate and party entry may increase with district magnitude under MMP, suggesting important directions for future investigation of MMP rules.  相似文献   
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