Carlisle E. Moody

Quality, Price, Advertising, and Published Quality Ratings

Economic literature contains several sometimes contradictory hypotheses concerning the relationships among quality, price, and advertising. We investigate the impact of published quality ratings on these relationships and find that quality and advertising are much more likely to be positively related in the presence of quality ratings.

The Lethal Effects of Three-Strikes Laws

Three‐strikes laws provide very long prison terms for certain criminals with prior convictions of serious violent crimes. It is likely that the laws increase homicides because a few criminals, fearing the enhanced penalties, murder victims and witnesses to limit resistance and identification. With a state‐level multiple‐time‐series design, we find that the laws are associated with 10–12 percent more homicides in the short run and 23–29 percent in the long run. The impact occurs in almost all 24 states with three‐strikes laws. Furthermore, there is little evidence that the laws have any compensating crime reduction impact through deterrence or incapacitation.

Age structure and crime rates: The conflicting evidence

Because arrest rates are especially high for teenagers and young adults, criminologists have long contended that age structure changes affect crime trends. In recent years, however, this belief has been drawn into question because crime has not declined even though high-crime age groups have shrunk. We argue that the age/crime relationship is probably exaggerated because the high arrest rates for younger persons are due partly to their lesser ability to escape arrest, younger persons commit more group crime, and the age structure of victims should be taken into account. We then review 90 studies that regress crime rates on age structure; only a small minority consistently finds significant relationships. Because of methodological problems in this research, one cannot conclude that the age/crime relationship does not exist, but the weight of evidence shows that forecasts based on demographic trends are not likely to be helpful.

Testing for the Effects of Concealed Weapons Laws: Specification Errors and Robustness

In 1997, John Lott and David Mustard published an important paper in which they found that right‐to‐carry concealed weapons laws reduce violent crime. Although Lott and Mustard appear to do all possible variations of the analysis, a closer reading reveals that the study might suffer from several possibly important errors. I reestimate the model and check for incorrect functional form, omitted variables, and possible second‐order bias in the t‐ratios. Lott and Mustards basic conclusions are generally robust with respect to these potential econometric problems. Overall, right‐to‐carry concealed weapons laws tend to reduce violent crime. The effect on property crime is more uncertain. I find evidence that these laws also reduce burglary.

The Impact of Prison Growth on Homicide

The major crime-reduction strategy in this country is to imprison more and more criminals. Past studies of its effectiveness in reducing homicide have produced wildly divergent results. The authors analyze the homicide-prison relationship with a time series over 1930-1994, finding that a 10% increase in prison population is associated with roughly 13% fewer homicides. The authors also studied assault and robbery, two crime types linked to homicide, and again found negative associations with prison population.

Guns and Crime

We estimate several models of handguns and crime based on state-level panel data for 1977–1998 using both General Social Survey data on gun availability and a new measure of handgun prevalence. We find that handguns have a negligible effect on crime. Apparently, there is either no causation between guns and crime, or a rough equilibrium between criminals who use guns in the commission of crime and ordinary citizens who use guns to defend themselves and deter crime.

The Impact of Right-to-Carry Concealed Firearm Laws on Mass Public Shootings

Right-to-carry (RTC) laws mandate that concealed weapon permits be granted to qualified applicants. Such laws could reduce the number of mass public shootings as prospective shooters consider the possibility of encountering armed civilians. However, these laws might increase the number of shootings by making it easier for prospective shooters to acquire guns. We evaluate 25 RTC laws using state panel data for 1977 through 1999. We estimate numerous Poisson and negative binomial models and find virtually no support for the hypothesis that the laws increase or reduce the number of mass public shootings.

On the Choice of Control Variables in the Crime Equation

Although control variables are the reason for multiple regression, surprising little attention is given to the process of locating and selecting the controls. If important controls are omitted, estimates can be biased and inconsistent whereas using too many controls can reduce efficiency and mask effects. We advocate a much broader search for controls than is customary, at least in the crime literature, and then the use of the general-to-specific methodology to select the relevant controls. We illustrate this procedure using a fixed effects panel data design evaluating the effect of legalized abortion on crime.

Age-structure trends and prison populations

Abstract This article explores the influence of age structure on the number of inmates in state prisons and the number of court commitments to prisons. Several studies had incorrectly predicted that the aging of the baby boom cohort would cause prison populations to decline in the 1990s, and this research endeavors to determine the reason for this failure. Using a multiple time series design with state data over approximately twenty years, the analysis regresses prison variables on the proportion of population in high-imprisonment-rate age groups (eighteen to twenty-four, twenty-five to thirty-four, and thirty-five to forty-four). A major finding is that age structure is, in fact, related to court commitments and prison populations. This is also true for both males and females when studied separately. The failure of predictions that prison commitments and population would decline is caused by other factors that have stronger impacts than age-structure trends. These trends will place downward pressures on future prison populations, but the trends cannot be used to forecast prison populations.

When Prisoners Get Out: The Impact of Prison Releases on Homicide Rates, 1975-1999

Although studies examining the relationship between prison populations and homicide rates find significant negative impacts, no published studies have examined the impact of prison releases on homicide. The issue here is whether release rates directly affect crime, independently of any impact they might have through their impact on prison populations. We examine this question by regressing homicide rates on prison release rates, prison population, and numerous control variables using panel data for 46 states from 1975 to 1999. The results provide no evidence of a significant positive relationship between prison releases and homicide. Similar to prior studies, however, we found that prison population growth has greatly reduced homicide rates. The main policy implication of these findings is that those leaving prison have no greater propensity to commit homicide than those entering or remaining in prison.