Variation In Homicide Rates Research Articles

US homicide rates increase when resources are scarce and unequally distributed.

As homicide rates spike across the United States, researchers nominate diverse causes such as temperature, city greenness, structural racism, inequality, poverty and more. While variation in homicide rates clearly results from multiple causes, many correlation studies lack the systematic theory needed to identify the underlying factors that structure individual motivations. Building on pioneering work in evolutionary human sciences, we propose that when resources are unequally distributed, individuals may have incentives to undertake high-risk activities, including lethal violence, in order to secure material and social capital. Here we evaluate this theory by analysing federal data on homicide rates, poverty and income inequality across all 50 US states for the years 1990, 2000 and 2005-2020. Supporting predictions derived from evolutionary social sciences, we find that the interaction of poverty (scarcity) and inequality (unequal distribution) best explains variation in US homicide rates. Results suggest that the increase in homicide rates during the height of the COVID-19 pandemic are driven in part by these same underlying causes that structure homicide rates across the US over the last 30 years. We suggest that these results provide compelling evidence to expand strategies for reducing homicide rates by dismantling structures that generate and concentrate sustained poverty and economic inequality.

Local violence and transitions to marriage and cohabitation in Mexico

AbstractObjectiveTo assess whether local violence is associated with the timing and type of women's first union formation.BackgroundLocal violence may cause disruptions to marriage markets and psychological and behavioral changes that may affect union formation patterns.MethodThe authors exploited the variation in homicide rates caused by a shift in national drug‐enforcement policy in Mexico in December 2006. Competing‐risks Cox models and union histories from a nationally representative survey of women (N = 33,292) were used to assess whether a recent increase in violence was associated with the timing of the first union transition, which could be either marriage or cohabitation. Analyses were conducted separately by education level.ResultsA recent increase in the local homicide rate was associated with delayed first marriage formation for less educated women. Supplementary analyses suggested that a decrease in the number of employed men per women, as well as reduced social interaction due to fear of victimization could be plausible causal mechanisms. No statistically significant associations were found between a recent increase in violence and transitions to first cohabitation for the less educated, or with any first union transition for the moderately and more educated.ConclusionAmong less educated women, a recent increase in violence was associated with a delayed entrance into marriage as a first union transition.ImplicationsBy increasing their barriers to marriage, local violence may contribute to the accumulation of disadvantage among disadvantaged women and families.

Absolute versus relative socioeconomic disadvantage and homicide: a spatial ecological case\u2013control study of US zip codes

BackgroundHomicide is a major cause of death and contributes to health disparities in the United States. This burden overwhelmingly affects people from racial and ethnic minority populations as homicide occurs more often in neighborhoods with high proportions of racial and ethnic minority residents. Research has identified that environmental factors contribute to variation in homicide rates between neighborhoods; however, it is not clear why some neighborhoods with high concentrations of racial and ethnic minority residents have high homicide rates while neighborhoods with similar demographic compositions do not. The aim of this study was to assess whether relative socioeconomic disadvantage, (i.e., income inequality), or absolute socioeconomic disadvantage (i.e., income) measured at the ZIP code- and state-levels, is associated with high homicide rates in US ZIP codes, independent of racial and ethnic composition.MethodsThis ecological case–control study compared median household income and income inequality in 250 ZIP codes with the highest homicide rate in our sample in 2017 (cases) to 250 ZIP codes that did not experience any homicide deaths in 2017 (controls). Cases were matched to controls 1:1 based on demographic composition. Variables were measured at both the ZIP code- and state-levels.ResultsLower median household income at the ZIP code-level contributed most substantially to the homicide rate. Income inequality at the state-level, however, was additionally significant when controlling for both ZIP code- and state-level factors.ConclusionsArea-based interventions that improve absolute measures of ZIP code socioeconomic disadvantage may reduce gaps in homicide rates.

Variations in Homicide Rates in Brazil: An Explanation Centred on Criminal Group Conflicts

This paper proposes an explanation for the variations in homicide rates in Brazil in the past two decades. Based on the comparison of ethnographic experiences lived in the criminal universe of four capital cities (São Paulo, Porto Alegre, São Luís and Maceió), we propose two analytical strategies: 1) the breakdown of quantitative homicide rate data by victim profile, and 2) the construction of historical synopses of conflicts between factions at the local level. We demonstrate how homicide rates, in specific socio-demographic profiles, oscillate based on changes in conflicts between factions at the local level conflicts, and influence variations in the aggregate rates.

Firms and Labor in Times of Violence: Evidence from the Mexican Drug War

I study how industrial development and employment in an emerging economy are affected by urban violence due to drug trafficking. Employing rich longitudinal plant-level data covering all of Mexico from 2005–2010, and exploiting plausibly exogenous spatiotemporal variation in homicide rates during the outbreak of drug-trade related violence in Mexico, commonly referred to as the Mexican Drug War, I show that a violent environment has a significant negative impact on manufacturing plants’ output, product scope, employment, and capacity utilization. The impact is very heterogeneous among plants. Studying within and cross-plant heterogeneity points to two underlying channels through which the Drug War affects firms: violence induced reduction in local demand and violence induced drop in labor supply participation. The output sensitivity of plants to a violent conflict increases in less diversified, locally selling and sourcing plants. The employment sensitivity increases with lower wages and a higher share of unskilled female workers. The results show both channels co-exist, and by reallocating resources from smaller, local, and female-intensive plants toward bigger and more diversified ones, the rise of drug violence has significant distortive effects on domestic industrial development in Mexico.

Direct and Indirect Effects of Individualism and Institutions on Homicides

The present paper evaluates whether people in highly individualistic cultures have a lower propensity to commit homicides, using data from 70 countries. Several previous papers report a significant negative correlation between these two variables, but it is not well established whether the effect of culture on this form of violent crime is direct or indirect. We estimate a structural equation model that includes: (a) the possibility that either culture or institutions affect the homicide rate, (b) a link between individualism and institutions and (c) credible exogenous information used as an instrumental variable for individualism. Our results show that individualistic nations generate a more effective judicial system, which is mainly responsible for the variation in homicide rates across countries. That is, individualism affects homicides only indirectly through the quality of legal institutions. We also find that different types of institutions have a similar relation to individualism, however, the moderating effect on homicides is more pronounced for legal or political institutions than for economic institutions.

Mapping disparities in homicide trends across Brazil: 2000\u20132014

BackgroundHomicides are a major problem in Brazil. Drugs and arms trafficking, and land conflicts are three of the many factors driving homicide rates in Brazil. Understanding long-term spatiotemporal trends and social structural factors associated with homicides in Brazil would be useful for designing policies aimed at reducing homicide rates.MethodsWe obtained data from 2000 to 2014 from the Brazil Ministry of Health (MOH) Mortality Information System and sociodemographic data from the Brazil Institute of Geography and Statistics (IBGE). First, we quantified the rate of change in homicides at the municipality and state levels. Second, we used principal component regression and k-medoids clustering to examine differences in temporal trends across municipalities. Lastly, we used Bayesian hierarchical space-time models to describe spatio-temporal patterns and to assess the contribution of structural factors.ResultsThere were significant variations in homicide rates across states and municipalities. We noted the largest decrease in homicide rates in the western and southeastern states of Sao Paulo, Rio de Janeiro and Espirito Santo, which coincided with an increase in homicide rates in the northeastern states of Ceará, Alagoas, Paraiba, Rio Grande Norte, Sergipe and Bahia during the fifteen-year period. The decrease in homicides in municipalities with populations of at least 250,000 coincided with an increase in municipalities with 25,000 people or less. Structural factors that predicted municipality-level homicide rates included crude domestic product, urbanization, border with neighboring countries and proportion of population aged fifteen to twenty-nine.ConclusionsOur findings support both a dissemination hypothesis and an interiorization hypothesis. These findings should be considered when designing interventions to curb homicide rates.

How does the welfare state reduce crime? The effect of program characteristics and decommodification across 18 OECD-countries

PurposeThe article revisits the negative effect of welfare state schemes on crime rates with a focus on the pathways of that effect. Social support theory (SST) and institutional anomie theory (IAT) are two related theoretical approaches to explain why – and how – the welfare state might prevent criminal behavior. This article tests the relevance of these theories for cross-country and over-time variation in homicide rates with more precise disaggregated welfare state indicators than used previously. MethodsWe use panel regressions with country fixed effects and data for 18 OECD countries between 1990 and 2011. Disaggregated cross-national social expenditure and benefit generosity data is used to discriminate between pathways of welfare state influence on cross-national homicide. ResultsThe welfare state suppresses crime particularly through social support via generous unemployment benefits. Overall decommodification, the key measure to test IAT, however, does not have any effect on homicide. ConclusionsOnly some welfare state interventions matter for homicide rates.

Drug‐related violence and the decline in the number of Mexican cross‐border workers

AbstractThis study examines how variations in homicide rates in Mexico are associated with the likelihood of participating in cross‐border work, that is, living in Mexico but working in the U.S. Based on Mexican census data from 2000, 2010, and 2015, and information on homicides, a series of ordinary least squares models are estimated to analyze the relationship between cross‐border commuting and homicide rates at the individual level. Fixed effects models are also estimated to study this relationship at the municipal level. The results show that from 2000 to 2010 the increase in homicide rates in northern border municipalities in Mexico reduced the likelihood of being a cross‐border worker, while from 2010 to 2015 the decrease in the homicide rate increased the probability that workers engage in cross‐border work. The decline in the number of cross‐border workers is likely in part a result of the escalation in drug‐related violence that may have led them to change their country of residence.

The Enduring Influence of Cohort Characteristics on Race-Specific Homicide Rates

AbstractThis study extends research on cohort effects and crime by considering how bifurcated population dynamics and institutional constraints explain variation in homicide rates across racial groups in the United States. Drawing upon the extensive research on racial residential segregation and institutional segmentation, we theorize how the criminogenic influences of cohort characteristics elucidated in prior work will be greater for Black cohorts than for White cohorts. We assess our hypothesis by estimating Age-Period-Cohort Characteristic models with data for the total population and separately for the Black and White populations over the 1975–2014 period. The results reveal persistent effects of relative cohort size and nonmarital births on Black cohort-specific homicide rates but null effects among the White population. These effects follow Black birth cohorts across the life course, leading to higher rates of both homicide arrest and homicide victimization.

Democratic Cultural Values as Predictors of Cross-National Homicide Variation in Europe

This study examines the extent to which variations in homicide rates across Europe, particularly differences between Western and Eastern Europe, can be explained by democratic cultural values. Prior studies have shown that individualism and egalitarianism promoted by democratic regimes are usually associated with lower levels of interpersonal violence. This study tests this relationship on a sample of 33 countries circa 2010. Not only does this relationship hold, but further analysis also shows that democratic values have both a direct and indirect effect on homicide rates as they are mediated by the strength of democratic institutions and practices.

Mortalidad por homicidios en México: tendencias, variaciones socio-geográficas y factores asociados

This study seeks to analyze the trend of homicide rates (total and by firearm) in Mexico between 1990 and 2009 and identify the variables that best explain the geographical variations of these rates in the 2008-2009 two-year period. Homicide rates, adjusted for age, were calculated for both sexes between 1990 and 2009 and for each state in 2008-2009. Factors associated with the interstate variations in the homicide rates were identified using multiple linear regression analysis. Results show that the homicide rate in Mexico decreased between 1990 and 2007, but doubled over the last two years (from 7.6 to 16.6 per 100,000). In 2009, the male homicide rate was almost 9 times higher than the female rate and about two-thirds of homicides involved firearms. Multivariate analysis reveals that impunity, drug trafficking, alcohol and drug consumption and school dropout in basic education - in that order - are key factors for understanding the geographical variations in homicide rates in Mexico in 2008-2009. Findings suggest that to reduce the number of homicide victims and spatial variations in the rate, it is necessary not only to fight the drug cartels, but above all to implement structural reforms in the criminal justice system and reduce the socioeconomic disparities among states.

POVERTY, INFANT MORTALITY, AND HOMICIDE RATES IN CROSS‐NATIONAL PERSPECTIVE: ASSESSMENTS OF CRITERION AND CONSTRUCT VALIDITY*

This paper assesses the extent to which the infant mortality rate might be treated as a "proxy" for poverty in research on cross-national variation in homicide rates. We have assembled a pooled, cross-sectional time-series dataset for 16 advanced nations over the 1993-2000 period that includes standard measures of infant mortality and homicide and also contains information on two commonly used "income-based" poverty measures: a measure intended to reflect "absolute" deprivation and a measure intended to reflect "relative" deprivation. With these data, we are able to assess the criterion validity of the infant mortality rate with reference to the two income-based poverty measures. We are also able to estimate the effects of the various indicators of disadvantage on homicide rates in regression models, thereby assessing construct validity. The results reveal that the infant mortality rate is more strongly correlated with "relative poverty" than with "absolute poverty," although much unexplained variance remains. In the regression models, the measure of infant mortality and the relative poverty measure yield significant positive effects on homicide rates, while the absolute poverty measure does not exhibit any significant effects. Our analyses suggest that it would be premature to dismiss relative deprivation in cross-national research on homicide, and that disadvantage is best conceptualized and measured as a multidimensional construct.

Homicide Rates in a Cross‐Section of Countries: Evidence and Interpretations

This study uses a regression analysis to explore the cross‐country variation in homicide rates for a large sample of countries. It starts by identifying seven significant regional variables, to which traditional socioeconomic, cultural, and institutional variables are added and tested. The importance of institutions, culture, and other factors affecting homicide rates is discussed. One unexpected finding is a curious relationship between the level of education and homicide rates: while an increase in male education tends to reduce homicide rates, an increase in female education tends to increase homicides. Several possible interpretations for this phenomenon are proposed. The study points to relatively unexplored areas of research in order to better understand homicide variation around the world.

The relative contribution of income inequality and imprisonment to the variation in homicide rates among Developed (OECD), South and Central American countries☆

Homicide rates vary widely across and within different continents. In order to address the problem of violence in the world, it seems important to clarify the sources of this variability. Despite the fact that income inequality and imprisonment seem to be two of the most important determinants of the variation in homicide rates over space and time, the concomitant effect of income inequality and imprisonment on homicide has not been examined. The objective of this cross-sectional ecological study was to investigate the association of income inequality and imprisonment with homicide rates among Developed (OECD), South and Central American countries. A novel index was developed to indicate imprisonment: the Impunity Index (the total number of homicides in the preceding decade divided by the number of persons in prison at a single slice in time). Negative binomial models were used to estimate rate ratios of homicides for young males and for the total population in relation to Gini Index and Impunity Index, controlling for infant mortality (as a proxy for poverty levels), Gross Domestic Product per-capita, education, percentage of young males in the population and urbanization. Both low income inequality and low impunity (high imprisonment of criminals) were related to low homicide rates. In addition, we found that countries with lower income inequality, lower infant mortality (less poverty), higher average income (GDP per-capita) and higher levels of education had low impunity. Our results are compatible with the hypothesis that both low income inequality and imprisonment of criminals, independent of each other and of other social-structural circumstances, may greatly contribute to the reduction in homicide rates in South and Central American countries, and to the maintenance of low levels of homicides in OECD countries. The Impunity Index reveals that countries that show greater commitment to education and to distribution of income also show greater commitment to punish serious criminal behavior.

Homicide and impunity: an ecological analysis at state level in Brazil

OBJECTIVE: To assess a new impunity index and variables that have been found to predict variation in homicide rates in other geographical levels as predictive of state-level homicide rates in Brazil. METHODS: This was a cross-sectional ecological study. Data from the mortality information system relating to the 27 Brazilian states for the years 1996 to 2005 were analyzed. The outcome variables were taken to be homicide victim rates in 2005, for the entire population and for men aged 20-29 years. Measurements of economic and social development, economic inequality, demographic structure and life expectancy were analyzed as predictors. An "impunity index", calculated as the total number of homicides between 1996 and 2005 divided by the number of individuals in prison in 2007, was constructed. The data were analyzed by means of simple linear regression and negative binomial regression. RESULTS: In 2005, state-level crude total homicide rates ranged from 11 to 51 per 100,000; for young men, they ranged from 39 to 241. The impunity index ranged from 0.4 to 3.5 and was the most important predictor of this variability. From negative binomial regression, it was estimated that the homicide victim rate among young males increased by 50% for every increase of one point in this ratio. CONCLUSIONS: Classic predictive factors were not associated with homicides in this analysis of state-level variation in Brazil. However, the impunity index indicated that the greater the impunity, the higher the homicide rate.

The relative contribution of income inequality and imprisonment to the variation in homicide rates among Developed (OECD), South and Central American countries

Homicide rates vary widely across and within different continents. In order to address the problem of violence in the world, it seems important to clarify the sources of this variability. Despite the fact that income inequality and imprisonment seem to be two of the most important determinants of the variation in homicide rates over space and time, the concomitant effect of income inequality and imprisonment on homicide has not been examined. The objective of this cross-sectional ecological study was to investigate the association of income inequality and imprisonment with homicide rates among Developed (OECD), South and Central American countries. A novel index was developed to indicate imprisonment: the Impunity Index (the total number of homicides in the preceding decade divided by the number of persons in prison at a single slice in time). Negative binomial models were used to estimate rate ratios of homicides for young males and for the total population in relation to Gini Index and Impunity Index, controlling for infant mortality (as a proxy for poverty levels), Gross Domestic Product per-capita, education, percentage of young males in the population and urbanization. Both low income inequality and low impunity (high imprisonment of criminals) were related to low homicide rates. In addition, we found that countries with lower income inequality, lower infant mortality (less poverty), higher average income (GDP per-capita) and higher levels of education had low impunity. Our results are compatible with the hypothesis that both low income inequality and imprisonment of criminals, independent of each other and of other social-structural circumstances, may greatly contribute to the reduction in homicide rates in South and Central American countries, and to the maintenance of low levels of homicides in OECD countries. The Impunity Index reveals that countries that show greater commitment to education and to distribution of income also show greater commitment to punish serious criminal behavior.

Assessing the Relevance of Anomie Theory for Explaining Spatial Variation in Lethal Criminal Violence: An Aggregate-Level Analysis of Homicide within the United States

One of the most influential statements in the anomie theory tradition has been Merton’s argument that the volume of instrumental property crime should be higher where there is a greater imbalance between the degree of commitment to monetary success goals and the degree of commitment to legitimate means of pursuing such goals. Contemporary anomie theories stimulated by Merton’s perspective, most notably Messner and Rosenfeld’s institutional anomie theory, have expanded the scope conditions by emphasizing lethal criminal violence as an outcome to which anomie theory is highly relevant, and virtually all contemporary empirical studies have focused on applying the perspective to explaining spatial variation in homicide rates. In the present paper, we argue that current explications of Merton’s theory and IAT have not adequately conveyed the relevance of the core features of the anomie perspective to lethal violence. We propose an expanded anomie model in which an unbalanced pecuniary value system – the core causal variable in Merton’s theory and IAT – translates into higher levels of homicide primarily in indirect ways by increasing levels of firearm prevalence, drug market activity, and property crime, and by enhancing the degree to which these factors stimulate lethal outcomes. Using aggregate-level data collected during the mid-to-late 1970s for a sample of relatively large social aggregates within the U.S., we find a significant effect on homicide rates of an interaction term reflecting high levels of commitment to monetary success goals and low levels of commitment to legitimate means. Virtually all of this effect is accounted for by higher levels of property crime and drug market activity that occur in areas with an unbalanced pecuniary value system. Our analysis also reveals that property crime is more apt to lead to homicide under conditions of high levels of structural disadvantage. These and other findings underscore the potential value of elaborating the anomie perspective to explicitly account for lethal violence.

The Geography of Homicide in São Paulo, Brazil

The authors investigate geographical patterns of homicide in São Paulo, Brazil. The geography of crime in developing world cities has been an underresearched area in part because of the lack of good-quality, geocoded offence data. In the case of São Paulo the availability of a new digital police dataset has provided the opportunity to improve our understanding of its crime patterns. The authors report the testing of hypotheses about the spatial variation in homicide rates. This variation is explained by poverty, situational conditions determined by differences in land use, and processes that indicate links with the geography of drug markets and the availability of firearms.

Acceptance of killing and homicide rates in nineteen nations

International variation in homicide rates may be attributable to cultural differences in acceptance of moral justifications for killing. The aim of this study is to investigate the relationships between measures of attitudes towards the justification of killing and homicide rates in diverse international populations. Four studies assessed variations in acceptance of killing among adults and young people in nineteen nations and four areas in the USA. Study 1 (1996-1997) assessed adult attitudes in Brazil, Chile, Costa Rica, Spain, and Venezuela with personal interviews in major cities. Study 2 (1999-2001) assessed attitudes among high school students in Denmark, Finland, Malta, Mexico, Netherlands, Slovenia, Sweden, Taiwan, and the UK with paper surveys administered in classrooms. Study 3 (2001) used telephone interviews to measure the equivalent attitudes among the US samples nationally and from regions in Texas. Study 4 (2002-2003) used paper surveys in classrooms to measure attitudes among high school students in Armenia, Belarus, Georgia, and the Russian Federation. The acceptance of killing varied significantly among genders and national/regional groups. The mean attitude scores in the four studies combined were significantly correlated with national/regional homicide rates and the amount of variance explained was similar to that for social inequality (GINI). Together the attitude scores and GINI explained 65% of the variance in homicide rates. This study provides evidence that variations in attitudes toward the justification of killing may be related to international differences in homicide rates.