Dimensions of competition in urban cannabis markets

We report the results of a survey of legal cannabis retail operators in the two largest urban centres of a Canadian province that uses a fully private model to determine the dimensions of competition between retail outlets. We find that, in addition to expected price and location competition, customer loyalty is central in the opinion of retailers. Firms also did not see the illicit market as their primary competition, instead identifying nearby legal retailers as their main competitors. Restrictions on advertising loomed large in the minds of retailers as a policy-based impediment to their success. These results are further supported by visual inspection of the exterior of all stores in one of the urban centres.     

The Effects of Immigrant Concentration on Changes in Neighborhood Crime Rates

Objectives

This study investigated the extent to which immigrant concentration is associated with reductions in neighborhood crime rates in the City of Los Angeles.

Methods

A potential outcomes model using two-stage least squares regression was estimated, where immigrant concentration levels in 1990 were used as an instrumental variable to predict immigrant concentration levels in 2000. The instrumental variables design was used to reduce selection bias in estimating the effect of immigrant concentration on changes in official crime rates between 2000 and 2005 for census tracts in the City of Los Angeles, holding constant other demographic variables and area-level fixed effects. Non-parametric smoothers were also employed in a two-stage least squares regression model to control for the potential influence of heterogeneity in immigrant concentration on changes in crime rates.

Results

The results indicate that greater predicted concentrations of immigrants in neighborhoods are linked to significant reductions in crime. The results are robust to a number of different model specifications.

Conclusions

The findings challenge traditional ecological perspectives that link immigrant settlement to higher rates of crime. Immigration settlement patterns appear to be associated with reducing the social burden of crime. Study conclusions are limited by the potential for omitted variables that may bias the observed relationship between immigrant concentration and neighborhood crime rates, and the use of only official crime data which may under report crimes committed against immigrants. Understanding whether immigrant concentration is an important dynamic of changing neighborhood patterns of crime outside Los Angeles will require replication with data from other U.S. cities.     

A forensic classification of distortion in human bite marks

The occurrence of distortion in human bite marks is well recognised. A forensic classification of distortion is suggested which is based upon the causative factors and their inter-relationships. The terms primary distortion and secondary distortion are introduced and described. The objective of this classification is to emphasise the need for a scientific approach to the recognition and interpretation of the types of distortion found in human bite marks. The relationships between distortion, distinctive features and superimposition techniques in bite mark analysis are discussed.     

纽约治安:业绩空前盖过批评声

在刚刚过去的2007年,纽约把暗杀案件数量降到自1963年以来的最低点(低于500起).它从1990年的2245起下降到这么个程度,无论是与全美各地横向比,还是与警察历史竖向比,都是首屈一指的.纽约人已经好久好久没有感激他们的警察队伍了. ……     

Simulation and Managerial Decision Making:A Double‐Loop Learning Framework

Systems approaches present opportunities for public managers and policy makers to view policies and programs in a broader context. This article presents a framework to explain how simulation modeling promotes double‐loop learning in management teams by building and exploring collective mental models as well as by enhancing accuracy of the mental models. The authors discuss the types of problems that may benefit from simulation modeling and illustrate how double‐loop learning occurs in the process of dynamic hypothesis testing. Using a case from New York State's Division of Disability Determination, the article shows how simulation modeling built confidence in a management team's decision by providing the team with tools to share and examine multiple hypotheses about a declining trend in initial disability recipients in the state between 1998 and 2004.     

Korea: Mythology and scholarship

The Origins of the Korean War, Volume 2, The Roaring of the Cataract 1947–1950, by Bruce Cumings. Princeton University Press, Princeton, NJ, 1990. xviii + 957 pp. $99.50. ISBN 0–691–07843–2.

Documents On British Policy Overseas, Series II, Volume IV, Korea 1950–1951, edited by H. J. Yasamee and K. A. Hamilton, assisted by Isabel Warner and Ann Lane. HMSO, London, 1991. liii + 513 pp. and 12 microfiches. £47. ISBN 0–11–591695–4.