The use of error rates to predict and characterize the efficacy of presumptive field tests

From a forensic perspective, a presumptive test, one which indicates the presence or absence of a certain target material such as blood, is an invaluable tool. Among these tests, there are different specificities, sensitivities, and shelf lives. The accuracy of a test is an algebraic combination of the specificity and sensitivity of the test. Each test has limitations as given by its false positive and false negative rates. The aim of this study was to illustrate how the false positive and false negative rates are to be properly determined using a simulation study for the phenolphthalein test. New presumptive tests must be properly evaluated/validated through testing of commonly encountered household items and other potentially probative items usually found at crime scenes, however, the makeup of test sets must appropriately capture all error rates. In order to correctly use these results when the test is applied to an unknown sample recovered at a crime scene, the error rates cannot be applied directly to estimate whether or not the sample is actually the analyte of interest. In a validation study, the forensic scientist calculates the false positive rate as the p(Positive Reaction|Blood), whereas at the scene, the crime scene investigator wishes to determine the p(Blood|Positive Reaction). All crime scene investigators need to ensure that the conditional is not transposed when interpreting such results. Furthermore, this work provides a model for the assessment of a multiple test diagnostic system intended for investigators.     

Timing and Appearance of Postmortem Root Banding in Nonhuman Mammals,

A study was undertaken using nonhuman mammal specimens to better understand environmental influences on postmortem hair root band (PMRB) formation and to see whether PMRBs would occur in nonhuman mammal hairs in a similar fashion to human hairs. Carcasses from surrounding roadways were the primary source of specimens for this study, augmented by donated deceased domestic pets. Sections of pelt from each specimen were placed in controlled environmental conditions while the remainder of the carcass was left in a secure outdoor setting. Hair samples were collected daily from outdoor and control specimens and examined for evidence of PMRBs. Several environmental factors were also recorded on a daily basis. Results demonstrate PMRBs can occur in nonhuman mammal hairs, and they have microscopic characteristics similar to human PMRBs. Factors found to correlate with PMRB formation include postmortem interval, temperature, pH, and the formation and subsequent volatilization of ammonia from the surrounding tissue.     

The downsides of information transmission and voting

I analyze a model of information transmission in collective choice environments. An Expert possesses private information about the consequences of passing an exogenous proposal and engages in cheap talk to persuade voters to pass or reject the proposal. The Expert may successfully persuade the voters to take her preferred action even when all or most voters would receive a better ex ante payoff with no information transmission. I consider several remedies that an institutional designer may consider in order to avoid this problem while allowing information transmission that benefits the voters. I evaluate the effects of (1) limiting Expert communication to binary endorsements, (2) encouraging competition between Experts, and (3) restricting the agenda in order to consider only one dimension at a time. None of these proposals completely eliminate negative persuasion outcomes, but limiting the Expert to binary endorsements avoids the worst manipulation while preserving beneficial information transmission.     

Using Cultural Theory to Analyze the Metagovernance of the Nuclear Renaissance in Britain,France, and the United States

The governments of Britain, France, and the United States are seeking to promote renewed investment in nuclear power through metagovernance. Metagovernance describes the way governments can leverage state power and resources to shape the behavior of networked actors to advance policy goals. To metagovern, governments use a variety of policy tools but the factors shaping the design of these policy tools remains unclear. Grid‐group cultural theory is used to show that the design of the policy tools used in metagovernance reflects both an underlying cultural bias within government and prevailing institutional circumstances. The paper demonstrates the utility of cultural theory in the study of metagovernance.     

Defending the Articles of Conferation: A Response to Sobel

A fundamental mystery of the Articles of Confederation is why the statescontributed sizeable resources to the confederation government when theywere allegedly caught in a collective action problem. In a recent article,Russel Sobel denies the collective action problem and suggests that ourresearch on the incentive structure of the confederation contradicts theevidence. This note clarifies both of our arguments, introduces the typeof evidence that would determine whether national public goods weresub-optimally supplied, and explains why states contributed in a mannerthat is consistent with the evidence and with a deficient institutionaldesign.     

The politics of partnerships: a study of police and housing collaboration to tackle anti-social behaviour on Australian public housing estates

This paper draws on the findings from a research project on partnership arrangements between the police and housing departments on three Australian public housing estates to tackle problems associated with illicit drug activity and anti-social behaviour (ASB). The analysis focused on the setting up of the partnerships and the interactions that followed from these institutional arrangements. The assumption that informs the paper is that when studying partnerships there is a need for a more critically framed analysis. The temptation to posit "a successful model" of what partnership entails and then to judge practices in relation to this model is considerable, but it inevitably falls into the trap of constructing a narrative of partnership success or failure in terms of individual agency (that is, the degree of commitment from individuals). The analysis undertaken in this paper has therefore sought to fathom a more complex set of organizational processes. Rather than confine the discussion to issues of success and failure, the study foregrounds the subjective accounts of individuals who work within partnership and the constraints they encounter. The paper therefore makes explicit the cultural tensions within and across agencies, contestation as to the extent of the policy "problem," and the divergent perspectives on the appropriate modes of intervention.     

Within cities and suburbs: Racial residential concentration and the spatial distribution of employment opportunities across sub‐metropolitan areas

This article examines and compares the spatial distributions of new jobs and people across sub‐metropolitan areas for Atlanta, Boston, Detroit, and Los Angeles. The jobs data come from the Multi‐City Study of Urban Inequality and the data on people come from the U.S. Bureau of the Census. The results indicate that less‐educated people, public assistance recipients, and especially poor females with children mostly reside in areas heavily populated by minorities where the availability of less‐skilled jobs is quite low, while the availability of these jobs relative to less‐educated people in suburban areas heavily populated by whites is high. Large fractions of the less‐skilled jobs in these metropolitan areas are not accessible by public transit. Furthermore, there is significant variation within both central cities and suburbs in the ethnic composition of residents and in less‐skilled job availability. The ability of various minority groups to gain employment in each area depends heavily on the ethnic composition of the particular area. © 2000 by the Association for Public Policy Analysis and Management.