How Smart Is my Dummy? Time Series Tests for the Influence of Politics

Kevin Grier Department of Economics, 335 Hester Hall, University of Oklahoma, Norman, OK 73019 e-mail: angus{at}ou.edu Of necessity, many tests for political influence on policiesor outcomes involve the use of dummy variables. However, itis often the case that the hypothesis against which the politicaldummies are tested is the null hypothesis that the interceptis otherwise constant throughout the sample. This simple nullcan cause inference problems if there are (nonpolitical) interceptshifts in the data and the political dummies are correlatedwith these unmodeled shifts. Here we present a method for morerigorously testing the significance of political dummy variablesin single equation models estimated with time series data. Ourmethod is based on recent work on detecting multiple regimeshifts by Bai and Perron. The article illustrates the potentialproblem caused by an overly simple null hypothesis, expositsthe Bai and Perron model, gives a proposed methodology for testingthe significance of political dummy variables, and illustratesthe method with two examples.

Before the curse of statisticsfell upon mankind we lived a happy, innocent life —HilaireBelloc, On Statistics

     

EFFECTS OF SKILL-BASED VERSUS INFORMATION-BASED DIVORCE EDUCATION PROGRAMS ON DOMESTIC VIOLENCE AND PARENTAL COMMUNICATION

This study used a pre- and postevaluation with a control group to compare the effectiveness of two divorce education programs: skill-based Children in the Middle (CIM) and informationbased Children First in Divorce (CFD). Each treatment group consisted of approximately 125 divorcing parents mandated to attend divorce education in Florida. The control group consisted of 64 divorcing parents not mandated to attend divorce education in Alabama for lack of a program. Treatment and control parents lived in comparable cities with comparable demographics. Results indicate that CIM, not CFD, improved parental communication. Both CIM and CFD reduced child exposure to parental conflict. Neither program had effects on domestic violence, actual parental conflict, or child behavior problems. Across all groups, parents with greater divorce knowledge and communication skills experienced more reciprocal discussions with the other parent, less parental conflict, less domestic violence, and they exposed children to less conflict.     

Felony-murder and community sentiment

The controversy over capital felony-murder resurfaced in two recent Supreme Court cases (Enmund v. Florida, 1982;Tison v. Arizona, 1987), where two bitterly divided Courts made highly questionable assertions regarding where community sentiment stood on this matter. To test these assertions about the felony-murder rule and the accessorial liability theory, two experiments were run (N=275, 73% death qualified, andN=212, 81% death qualified) where mock jurors rendered verdicts and sentences for four defendants who varied in their level of culpability and level of participation in the crime. To test the Supreme Court's reasoning, subjects rendered decisions and reasons using the “ninth Justice” paradigm, where they could “reverse and remand” or “let stand” the death sentence for felony-murder. The empirical evidence indicates that subjects clearly and consistently reject the accessorial liability theory and the felony-murder rule, and these results refute the majority's assertions inTison about where community sentiment stands.     

Representative Democracy as a Necessary Condition for the Survival of a Federal Constitution

It does not follow from the supposition that the union is beneficialthat its terms would go unchallenged by its members. The argumentin this article suggests that federal stability (robustness)requires for itself a well-functioning democratic process, whichsatisfies a fairly restrictive condition. A necessary conditionfor the resiliency of the federal regime is a representativedemocracy; furthermore, it is the representative democracy inwhich rewards to the representatives are only in part vestedin their parochial constituencies, while in the other part comeform other sources, e.g., from an oversized at-large coalition.The requirement to the democratic process is, of course, onlya necessary, not a sufficient condition for the federal success.Yet, we argue in this essay that only the states with well-developed(properly institutionalized) democratic electoral competitionhave a chance to form a resilient federal union and sustaintheir federal constitutional arrangements not just in form,but in their political practice as well.     

Characterization of the Caucasian haplogroups present in the SWGDAM forensic mtDNA dataset for 1771 human control region sequences. Scientific Working Group on DNA Analysis Methods

Currently, the Scientific Working Group on DNA Analysis Methods (SWGDAM) mtDNA dataset is used to infer the relative rarity of mtDNA profiles (i.e., haplotypes) obtained from evidence samples and for identification of missing persons. The Caucasian haplogroup patterns in this forensic dataset have been characterized using phylogenetic methods. The assessment reveals that the dataset is relevant and representative of U.S. and European Caucasians. The comparisons carried out were both the observation of variable sites within the control region (CR) and the selection of a subset of these sites, which partition the variation within human mtDNA control region sequences into clusters (i.e., haplogroups). The aligned sequence matrix was analyzed to determine both single nucleotide polymorphisms (SNPs) in a phylogenetic context, as well as to check and standardize haplogroup designations with a focus on determining the characters that define these groups. To evaluate the dataset for forensic utility, the haplogroup identifications and frequencies were compared with those reported from other published studies.