Kenneth C. Land

Structural Covariates of Homicide Rates: Are There Any Invariances Across Time and Social Space?

This study demonstrate that the empirical literature on the structural convariates of homicide rates contains inconsistent findings across different time periods and different geographical units. This apparent variance of findings may be due to statistical or methodological artifacts of particular studies, such as different time periods covered, units of analysis, samples, model specification, and problems of statistical analysis and inference. A baseline regression model using 11 structural covariates is estimated for cities, metropolitan areas, and states in 1960, 1970, and 1980. The empirical estimates of this model exhibit instability because of high levels of collinearity among several regressors. Principal components analysis is applied to simplify the dimensionally of the structural covariate space. Reestimation of the regression model then indicates that the apparent inconsistencies across time and social space are greatly reduced. The theoretical significance of the findings for substantive theories of violent crime are discussed.

Social Inequality and Predatory Criminal Victimization: An Exposition and Test of a Formal Theory

This study systematically tests a formal theory of how certain dimensions of social stratification--income, race, and age--relate to risk of predatory criminal victimization. An opportunity theory of criminal victimization is proposed, focusing on the mediating role played by five risk factors: exposure, guardianship, proximity to potential offenders, attractiveness of potential targets, and definitional properties of specific crimes themselves. Propositions are derived pertaining to the bivariate and multivariate-partial (main) effects expected from the theory and tested in analyses based on a representative sample of the U.S. population for the crimes of assault, burglary, and personal larceny. These data indicate that the relationship between the dimensions of social stratification and the offenses studied here is complex, and that, other things being equal, those usually thought to be most vulnerable economically and socially--the poor, the nonwhite, the old--are not the most likely victims of crime. Race has little direct effect on victimization risk, while age is inversely related to each type of crime at both the bivariate and multivariate levels of analyses. The findings are largely consistent with the proposed theory. (abstract Adapted from Source: American Sociological Review, 1981. Copyright

UNEMPLOYMENT AND CRIME RATES IN THE POST- WORLD WAR II UNITED STATES: A THEORETICAL AND EMPIRICAL ANALYSIS

Using annual time-series data for the United States, 1946-1982, two hypotheses are tested: (1) The level of the unemployment rate in any given year will have a negative partial contemporaneous effect on detrendedfluctuations (increases or decreases) in seven Index Crime rates (homicide, rape, aggravated assault, robbery, burglary, larceny-theft, and motor vehicle theft) in that year. (2) Unemployment-rate fluctuationsfrom one year to the next will have a positive partial effect on detrended crime-rate fluctuations in the next year. These hypotheses are developed from a theoretical model that identifies the former with a criminal opportunity effect, and the latter with a criminal motivation effect, of aggregate unemployment on crime. For burglary, robbery and larceny-theft, empirical support is found for the expected pattern of partial effects. However, the relative sizes of the effects are such that the total impacts of unemployment-through both partial effects-are negative. In addition, only the negative-levels effect is exhibited for homicide and motor vehicle theft, while rape and aggravated assault show no consistent association with either levels orfluctuations in the unemployment rate. Interpretations for these findings are discussed.

Quality of life indexes for national policy: review and agenda for research

A number of governments and public policy institutes have developed “Quality of Life Indexes” – statistics that attempt to measure the quality of life for entire states or regions. We develop 14 criteria for determining the validity and usefulness of such QOL indexes to public policy. We then review 22 of the most-used QOL indexes from around the world. We conclude that many of the indexes are successful in that they are reliable, have established time series measures, and can be disaggregated to study subpopulations. However, many fall short in four areas: (1) indexes vary greatly in their coverage and definitions of domains of QOL, (2) none of the indexes distinguish among the concepts of input, throughput, and output that are used by public policy analysts, (3) they fail to show how QOL outputs are sensitive to public policy inputs, and (4) none have examined convergent validity against each other. We conclude that many of these indexes are potentially very useful for public policy and recommend research to further improve them.

Educational status and active life expectancy among older blacks and whites.

BACKGROUND AND METHODS Persons of low socioeconomic status are known to have reduced life expectancy. In a study of the relation of socioeconomic status to disability-free or active life expectancy among older persons, we analyzed prospectively gathered data on 2219 blacks and 1838 whites who were 65 years of age or older in the Piedmont region of North Carolina. We defined disability as the inability to perform independently one or more basic functional activities such as walking, bathing, dressing, eating, and using the toilet. For subgroups defined by sex, race, and education, statistical models were used to estimate, for persons at each year of age, the probability of transition from not being disabled or being disabled at base line to not being disabled, being disabled, or having died one year later. These transition probabilities were then entered into increment-decrement life tables to generate estimates of total, active, and disabled life expectancy (with total life expectancy equal to active life expectancy plus disabled life expectancy). RESULTS Sixty-five-year-old black men had a lower total life expectancy (11.4 years) and active life expectancy (10 years) than white men (total life expectancy, 12.6 years; active life expectancy, 11.2 years), although the differences were reduced after we controlled for education. The estimates for 65-year-old black women (total life expectancy, 18.7 years; active life expectancy, 15.9 years) were similar to those for white women. Black men and women 75 years old and older had higher values for total life expectancy and active life expectancy than whites, and the differences were larger after stratification for education. Education had a substantially stronger relation to total life expectancy and active life expectancy than did race. At the age of 65, those with 12 or more years of education had an active life expectancy that was 2.4 to 3.9 years longer than the values for those with less education in all the four subgroups defined by sex and race. Overall, the subgroups with longer total life expectancy and active life expectancy also lived more years with a disability. CONCLUSIONS Among older blacks and whites, the level of education, a measure of socioeconomic status, has a greater effect than race on total life expectancy and active life expectancy.

Principles of Path Analysis

Sociologists have used for some time the methods of classical statistics in the interpretation of many varieties of sociological data. However, due to the lack of a procedure for incorporating statistical results into social theory, parameter estimates have seldom had a direct bearing on the evaluation and reformulation of sociological theory. This state of affairs has stimulated recent discussions of linear causal models as a procedure for bridging the gap between sociological theory on the one hand and the results of classical statistical analysis on the other. Although variations in emphasis exist, the essential idea of the causal model involves the construction of an oversimplified model of reality in the sense that the model considers only a limited number of variables

Resolving inconsistencies in trends in old-age disability: Report from a technical working group

In September 2002, a technical working group met to resolve previously published inconsistencies across national surveys in trends in activity limitations among the older population. The 12-person panel prepared estimates from five national data sets and investigated methodological sources of the inconsistencies among the population aged 70 and older from the early 1980s to 2001. Although the evidence was mixed for the 1980s and it is difficult to pinpoint when in the 1990s the decline began, during the mid- and late 1990s, the panel found consistent declines on the order of 1%–2.5% per year for two commonly used measures in the disability literature: difficulty with daily activities and help with daily activities. Mixed evidence was found for a third measure: the use of help or equipment with daily activities. The panel also found agreement across surveys that the proportion of older persons who receive help with bathing has declined at the same time as the proportion who use only equipment (but not personal care) to bathe has increased. In comparing findings across surveys, the panel found that the period, definition of disability, treatment of the institutionalized population, and age standardizing of results were important to consider. The implications of the findings for policy, national survey efforts, and further research are discussed.

How Many Latent Classes of Delinquent/Criminal Careers? Results from Mixed Poisson Regression Analyses

This article reviews questions about different categories of criminal careers, summarizes Poisson latent class regression models, describes procedures for evaluating the optimal number of latent classes, and applies this methodology to data from male cohorts taken from the cities of London, Philadelphia, and Racine. Four latent classes of offending careers is an appropriate number for the London cohort, but five classes can be justified for the Philadelphia data. In the case of the Racine cohorts, five classes may be detected for the 1942 and 1955 cohorts but only four for the 1949 cohort. Despite the varying numbers of latent offending classes, there clearly is a small number of typical age patterns.

Cumulative Deficits Better Characterize Susceptibility to Death in Elderly People than Phenotypic Frailty: Lessons from the Cardiovascular Health Study

OBJECTIVES: To compare how well frailty measures based on a phenotypic frailty approach proposed in the Cardiovascular Health Study (CHS) and a cumulative deficits approach predict mortality.

A Comparison of Poisson, Negative Binomial, and Semiparametric Mixed Poisson Regression Models With Empirical Applications to Criminal Careers Data

Specifications and moment properties of the univariate Poisson and negative binomial distributions are briefly reviewed and illustrated. Properties and limitations of the corresponding poisson and negative binomial (gamma mixtures of Poissons) regression models are described. It is shown how a misspecification of the mixing distribution of a mixed Poisson model to accommodate hidden heterogeneity ascribable to unobserved variables—although not affecting the consistency of maximum likelihood estimators of the Poisson mean rate parameter or its regression parameterization—can lead to inflated t ratios of regression coefficients and associated incorrect inferences. Then the recently developed semiparametric maximum likelihood estimator for regression models composed of arbitrary mixtures of Poisson processes is specified and further developed. It is concluded that the semiparametric mixed Poisson regression model adds considerable flexibility to Poisson-family regression models and provides opportunities for interpretation of empirical patterns not available in the conventional approaches.