Practice narratives enhance children’s memory reports

Practicing recall of a non-target event prior to discussing substantive issues is a relatively new recommendation for interviews with child victims and witnesses. Despite evidence of the effectiveness of these practice narratives in obtaining detailed reports from children, specific recommendations about the duration and content of these interviews have yet to be systematically investigated. In the present study, 176 children aged 6–10 years watched a magic show and then participated in an interview that began with a practice narrative, with varying length (2 or 5 minutes) and topics (unique or commonplace), or no practice narrative. Conducting a practice narrative of any kind was beneficial to children's subsequent recall of accurate details over no practice narrative. Benefits to children's accurate recall were observed with as little as 2 minutes of practice and practice narratives were particularly beneficial if a unique, rather than commonplace, experience was targeted for practice recall. The present results confirm previous field research and laboratory findings indicating that the substantive phase of the interview is enhanced by conducting a practice narrative and extends the benefits of practice narratives to even a very brief practice narrative.     

Polarization and Policy: The Politics of Public‐Sector Pensions

For decades, America's state and local governments have promised their workers increasingly generous pensions but failed to fully fund them, producing a fiscal problem of staggering proportions. In this article, we examine the politics of public pensions. While mainstream theoretical ideas in the American politics literature would suggest the pension issue should be polarized, with Democrats pushing for generous pensions over Republican resistance, we develop an argument—rooted in more traditional theoretical work by Schattschneider, Lowi, Wilson, and others—implying that both parties should be expected to support generous pensions during normal times and that only after the onset of the Great Recession, which expanded the scope of conflict, should the parties begin to diverge. Using a new data set of state legislators' votes on hundreds of pension bills passed between 1999 and 2011, we carry out an empirical analysis that supports these expectations.     

The Crime Kuznets Curve

Objectives

Criminologists have long studied the relationship between economic conditions and crime. Empirical evidence is inconclusive, pointing at different directions. This may reflect the conflicting theoretical predictions on the relationship between these phenomena, but also the prevailing methodological choice which focuses on linear relationships even though nonlinearities are plausible theoretically.

Methods

In this paper, we revisit the empirical relationship between economic conditions and crime by exploring potential nonlinearities. We look at flexible parametric specifications that include up to a cubic term of per capita income (or one dummy for each income quintile) and nonparametric and semi-parametric specifications (such as General Additive Models). Our results are robust to controlling for the standard socioeconomic, demographic, and policy determinants of crime, as well as to including a lagged dependent variable or state and time fixed effects.

Results

We document the existence of an inverted U-shaped relationship between crime and income within US states for the period 1970-2011. Crime increases with per capita income until it reaches a maximum, and then decreases as income keeps rising. This “Crime Kuznets Curve” (CKC) exists for property crime and for categories of violent crime that can be related to economic appropriation, like robbery, and is less robust for violent crimes not connected to economic incentives. We show that this pattern cannot be explained by correlated changes in economic inequality or by changes in law enforcement.

Conclusions

In addition to providing robust evidence of the existence of a CKC, our findings lay the groundwork for studies exploring the underlying theoretical mechanisms. These should go beyond income inequality or law enforcement, and should explain why the results hold more clearly for property than for violent crime. Our findings and subsequent research to understand the underlying drivers are relevant for policy, as they suggest that violent conflict cannot be tackled solely by the trickle-down forces of economic growth.

     

Meet the Narco: increased competition among criminal organisations and the explosion of violence in Mexico

Several previous studies have found that interventions by security forces against criminal organisations result in increased violence related to organised crime. However, much less is known about how and why this effect occurs. Our study not only identifies the causal mechanisms that explain this outcome, but also evaluates the empirical validity of these mechanisms. Employing a novel data set, we find that following security-force intervention, the number of criminal organisations increases, and such greater fragmentation in turn raises the incidence of violence among criminal organisations as the relative power of the organisations changes. We employ a mediation model to verify the existence of these causal mechanisms. In addition, we find a decreasing rate of rise in levels of violence as the number of organisations increases.     

Contextual Stress and Health Risk Behaviors Among African American Adolescents

This study examined the longitudinal association between contextual stress and health risk behaviors and the role of protective factors in a community epidemiologically-defined sample of urban African American adolescents (N = 500; 46.4% female). Structural equation modeling was used to create a latent variable measuring contextual stress (community violence, neighborhood disorder, and experiences with racial discrimination). Contextual stress in 8th grade was associated with aggressive behavior and substance use 2 years later for boys. For girls, contextual stress predicted later substance use, but not aggressive behavior. High academic competence and self-worth reduced the impact of contextual stress on substance use for boys. Implications for intervention and directions for future research on health risk behaviors among African American adolescents are discussed.     

Quantification of human mitochondrial DNA using synthesized DNA standards

Successful mitochondrial DNA (mtDNA) forensic analysis depends on sufficient quantity and quality of mtDNA. A real-time quantitative PCR assay was developed to assess such characteristics in a DNA sample, which utilizes a duplex, synthetic DNA to ensure optimal quality assurance and quality control. The assay's 105-base pair target sequence facilitates amplification of degraded DNA and is minimally homologous to nonhuman mtDNA. The primers and probe hybridize to a region that has relatively few sequence polymorphisms. The assay can also identify the presence of PCR inhibitors and thus indicate the need for sample repurification. The results show that the assay provides information down to 10 copies and provides a dynamic range spanning seven orders of magnitude. Additional experiments demonstrated that as few as 300 mtDNA copies resulted in successful hypervariable region amplification, information that permits sample conservation and optimized downstream PCR testing. The assay described is rapid, reliable, and robust.