Positive Neighborhood Effects Research Articles

Distinguishing neighborhood and individual social risk factors in health care.

To investigate (a) the magnitude of the independent associations of neighborhood-level and person-level social risk factors (SRFs) with quality, (b) whether neighborhood-level SRF associations may be proxies for person-level SRF associations, and (c) how the association of person-level SRFs and quality varies by neighborhood-level SRFs. 2015-2016 Medicare Advantage HEDIS data, Medicare beneficiary administrative data, and 2016 American Community Survey (ACS). Mixed effects linear regression models (1) estimated overall inequities by neighborhood-level and person-level SRFs, (2) compared neighborhood-level associations to person-level associations, and (3) tested the interactions of person-level SRFs with corresponding neighborhood-level SRFs. Beneficiary-level SES and disability administrative data and five-year ACS neighborhood-level SRF information were each linked to HEDIS data. For all or nearly all HEDIS measures, quality was worse in neighborhoods lower in SES and in neighborhoods with higher proportions of residents with a disability. Quality by neighborhood racial and ethnic composition was mixed. Accounting for corresponding person-level SRFs reduced neighborhood SRF associations by 25% for disability, 43% for SES, and 74%-102% for racial and ethnic groups. Person-level SRF coefficients were not consistently reduced in models that added neighborhood-level SRFs. In 19 of 35 instances, there were significant (p < 0.05) interactions between neighborhood-level and corresponding person-level SRFs. Significant interactions were always positive for disability, SES, Black, and Hispanic, indicating more negative neighborhood effects for people with SRFs that did not match their neighborhood and more positive neighborhood effects for people with SRFs that matched their neighborhood. Relying solely on neighborhood-level SRF models that omit similar person-level SRFs overattributes inequities to neighborhood characteristics. Neighborhood-level characteristics account for much less variation in these measures' scores than similar person-level SRFs. Inequity-reduction programs may be most effective when targeting neighborhoods with a high proportion of people with a given SRF.

A fungal endophyte of an annual weed reduces host competitive ability and confers associational protection to wheat

Epichloid fungal endophytes (Epichloë spp., Ascomycota: Clavicipitaceae) inhabit aerial tissues of several cool-season grasses, and enhance host growth and defence against herbivores. The presence of these symbionts can also affect interactions between the host and other non-epichloid plants. The role of an epichloid endophyte on interspecific competition has been tested using perennial grasses with contrasting results, but it has been scarcely tested using annual species in agroecosystems. We evaluated the impact of Epichloë-grass symbiosis on the competitive interaction between a non-host cereal crop (Triticum aestivum, wheat) and a host weed (Lolium multiflorum, ryegrass), growing in the presence of invertebrate herbivores (aphids) under no resource limitation. We conducted an outdoor mesocosm experiment with wheat plants growing in monoculture or in mixture with low or high proportions of ryegrass plants. Ryegrass plants presented either low (E-) or high (E+) incidence of Epichloë occultans (i.e. frequency of epichloid endophytic plants). We measured wheat vegetative and reproductive yield and its natural aphid infestation. Although epichloid endophyte incidence did not affect ryegrass biomass, wheat reproductive yield in mixtures (relative to wheat monocultures) was 45% higher when grown with E+ ryegrass plants than E- conspecific plants. Aphids preferred wheat plants grown with E- plants rather than wheat plants grown with E+ plants, but only in mixtures with high proportion of ryegrass. Our results demonstrate that epichloid endophyte incidence can decrease host competitive ability and confers associational protection to the non-endophytic neighbouring plants. Thus, ryegrass-endophyte symbiosis can increase crop yield by positive neighbourhood effects through different mechanisms probably related to the density of the weed. The benefits of this endosymbiont cannot be considered host-exclusive since they can be disseminated to non-endophytic plants. Furthermore, our results suggest that the epichloid endophyte incidence on annual weeds can contribute to agroecosystem sustainability by influencing pest management and increasing crop yield.

Neighbourhood and school effects on educational inequalities in the transition from primary to secondary education in Amsterdam

Drawing on an advanced analysis of individual longitudinal register data of school careers of four cohorts of children in Amsterdam, this article suggests that school advice is highly differentiated between children of different migrant and socioeconomic backgrounds. Moreover, apart from these individual characteristics, we demonstrate that the socioeconomic composition of neighbourhoods and schools is important for understanding differences in school advice. The analysis shows that neighbourhood and school socioeconomic disadvantage negatively affects the school advice of children with highly educated parents, while socioeconomic advantage positively affects all children and especially children of lower- and intermediate-educated parents. The positive neighbourhood effects are, however, mediated by primary school context. We suggest that while most of the educational inequalities may be explained by individual characteristics, residential and school segregation intensify these inequalities, especially through the beneficial effects of neighbourhood and school advantage.

The Impact of Sports Stadiums on Localized Commercial Activity: Evidence from a Business Improvement District

Local government funding of sports stadiums is frequently justified as stimulating economic activity despite consensus contrary findings in the academic literature. Though some studies have identified positive neighborhood effects from stadiums on nearby residential property, scant research exists regarding impacts on highly-localized commercial activity that is hypothesized to spur further local economic development. This analysis exploits the recent relocation of a professional baseball team from downtown Atlanta to a pre-existing Georgia Business Improvement District (Community Improvement District or CID) in suburban Cobb County to estimate the impact of the stadium development on commercial property values. The existence of multiple CIDs in the metro-Atlanta area provides the opportunity to estimate a counterfactual comparison absent the stadium to draw causal inference regarding the stadium’s impact on economic activity using the synthetic control method. Estimates do not identify increased commercial property values in the district following the stadium opening, which is consistent with past studies that find little to no positive impact on economic activity. The results indicate that previous findings of positive impacts on residential property may not be applicable to commercial property.

Race to safety: Political competition, neighborhood effects, and coal mine deaths in China

When political agents are subject to centralized performance evaluation, their efforts and performances tend to be correlated with one another in the “neighborhood”. Using quarterly data from prefecture-level cities in China, this paper finds evidence of positive neighborhood effects on coal mine deaths: the number of accidental deaths in a city is positively associated with those in its political neighbors. The neighborhood effects are confined by provincial borders, but do not diminish as the geographic scope of the neighborhood increases. Moreover, the effects are amplified by regulatory reforms and political cycles that increase the salience of coal mine safety. The findings of neighborhood effects on coal mine deaths are consistent with the logic of relative performance evaluation (RPE) as a mechanism for shaping policy outcomes.

Forest dynamics.

Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics stabilized by high-severity and low-severity disturbance regimes. Contrary to prevailing ecological theory, systems with positive neighborhood effects can have similar levels of compositional stability across tree, stand, and landscape scales. Neighborhood effect theory can help explain responses of landscapes to large-scale land clearing and novel effects brought on by factors such as invasive species and deer overabundance.

Response of mountain Picea abies forests to stand‐replacing bark beetle outbreaks: neighbourhood effects lead to self‐replacement

Summary Large, severe disturbances drive many forest ecosystems over the long term, but pose management uncertainties when human experience with them is limited. Recent continent‐scale outbreaks of bark beetles across the temperate Northern Hemisphere have raised major concerns as to whether coniferous forests will regenerate back towards pre‐outbreak condition and meet possible reforestation objectives. To date, however, analyses of post‐outbreak regeneration across broad spatial and temporal scales have been rare, and entirely lacking for many regions. Following a series of large, severe ( 99% overstorey mortality) outbreaks of spruce bark beetles Ips typographus in Central Europe, we capitalized on an extensive forest inventory data set (n = 615 plots across 7000 ha) to evaluate regeneration dynamics in Norway spruce Picea abies forests across the Bohemian Forest Ecosystem (spanning Germany and the Czech Republic). We asked whether neighbourhood effects (conspecific advance regeneration of spruce) would support prompt regeneration back to spruce forest, or whether the rapid, severe canopy mortality would overwhelm this influence and promote pioneer and broadleaf species. We tracked 15 years of post‐outbreak regeneration dynamics (occupancy, density, height, composition) of all tree species and evaluated initial variations in successional pathway and structure. Median tree regeneration density increased from 400 trees ha−1 at the time of outbreak to 2000 trees ha−1 within a decade, and occupancy increased from 58% to 76%. The increases were driven by spruce, which primarily recruited from advance regeneration, gradually occupying greater height classes. Only one broadleaf/pioneer species increased in relative proportion, for a brief (&lt;3‐year) period before declining again. Nevertheless, both pure spruce and spruce–broadleaf stands were common and, coupled with wide variations in density and height, contributed to diverse early‐successional structure. Synthesis and applications. Contrary to common expectations, spruce beetle outbreaks in Central Europe effectively promoted their host in the long term. Outbreak‐affected forests are naturally self‐replacing even after severe canopy mortality, when positive neighbourhood effects of conspecific advance regeneration lead to rapid replacement of the dominant species. Thus, natural regeneration may be considered among the most effective ways to meet possible reforestation objectives in forests destroyed by beetles.

Hurricane Katrina as an Experiment in Housing Mobility and Neighborhood Effects: Were the Relocated Poor Black Evacuees Better-Off?

Hurricane Katrina induced hundreds of thousands of New Orleans citizens to evacuate and relocate to different neighborhoods. Some of these evacuees moved to neighborhoods with poverty rates lower than the one they left in New Orleans. With survey data on a small sample of black Katrina evacuees who registered for absentee voter ballots, this paper explores whether or not there were improvements in the welfare of black evacuees— neighborhood effects—as a result of moving to neighborhoods with a lower poverty rate. With data from a small sample of relocated Katrina evacuees, we provide matching estimates of the short-run treatment effect of different types of changes in neighborhood poverty on five different measures of individual welfare. Treatment parameter estimates reveal—conditional upon the change in origin to destination neighborhood poverty rate—positive neighborhood effects mostly for black evacuees who did not move from high poverty to low poverty neighborhoods, but could have. Our results suggest that at least in the short-run, antipoverty policies based on housing mobility and changing the poverty characteristics of neighborhoods are not necessarily effective in improving the welfare of poor black households.

Distance to Growing Markets and Sub‐Saharan African Exports*

Abstract: A typical person in sub‐Saharan Africa is a long way from world markets and is further from world markets now than in 1980. This partly reflects slower growth within Africa than for the world as a whole. Despite slower growth in Africa, African exports have become increasingly regionalized. By 2005, a country in Africa typically exported more than twice as much to a country in its own region as would be expected based on economic size and bilateral distance. This regionalization was not present in the early 1980s and has become stronger over time. We find evidence of positive neighborhood effects through exports, but sub‐Saharan countries benefit less from growth in their own region than this typical relationship indicates. Given the small share of exports destined to their neighbors, low‐income countries in sub‐Saharan Africa experience relatively modest export growth from growth in the region. These factors imply that African countries are unlikely to pull each other out of poverty and a regional focus may be less effective than a focus on countries outside of the region.

Complementarity and Custom in Wage Contract Violation

Abstract We present and estimate a model with strategic complementarities in firms' choices of on-time or delayed wage payment. Linked employer-employee panel data from Russia facilitate identification of the endogenous interactions through fixed effects for firms, workers, and local labor markets, and instrumental variables based on policy interventions. The estimated reaction function displays strongly positive neighborhood effects, and the estimated feedback loops—worker quits, effort, strikes, and legal penalties—imply that costs of wage delays are attenuated by neighborhood arrears. We also study a nonlinear case with two stable symmetric equilibria: a punctual payment and a late payment equilibrium.

Understory vegetation in old-growth and second-growth Tsuga canadensis forests in western Massachusetts

We compared the understory communities (herbs, shrubs, and tree seedlings and saplings) of old-growth and second-growth eastern hemlock forests ( Tsuga canadensis) in western Massachusetts, USA. Second-growth hemlock forests originated following clear-cut logging in the late 1800s and were 108–136 years old at the time of sampling. Old-growth hemlock forests contained total ground cover of herbaceous and shrub species that was approximately 4 times greater than in second-growth forests (4.02 ± 0.41%/m 2 versus 1.06 ± 0.47%/m 2) and supported greater overall species richness and diversity. In addition, seedling and sapling densities were greater in old-growth stands compared to second-growth stands and the composition of these layers was positively correlated with overstory species composition (Mantel tests, r > 0.26, P < 0.05) highlighting the strong positive neighborhood effects in these systems. Ordination of study site understory species composition identified a strong gradient in community composition from second-growth to old-growth stands. Vector overlays of environmental and forest structural variables indicated that these gradients were related to differences in overstory tree density, nitrogen availability, and coarse woody debris characteristics among hemlock stands. These relationships suggest that differences in resource availability (e.g., light, moisture, and nutrients) and microhabitat heterogeneity between old-growth and second-growth stands were likely driving these compositional patterns. Interestingly, several common forest understory plants, including Aralia nudicaulis, Dryopteris intermedia, and Viburnum alnifolium, were significant indicator species for old-growth hemlock stands, highlighting the lasting legacy of past land use on the reestablishment and growth of these common species within second-growth areas. The return of old-growth understory conditions to these second-growth areas will largely be dependent on disturbance and self-thinning mediated changes in overstory structure, resource availability, and microhabitat heterogeneity.

Complementarity and Custom in Wage Contract Violation

We analyze a model of wage delay in which strategic complementarity arises because each employer's costs of violating its contracts decrease with the arrears in its labor market. The model is estimated on panel data for workers and firms in Russia, facilitating identification through fixed effects for employees, employers, and local labor markets, and instrumental variables based on policy interventions. The estimated reaction function displays strongly positive neighborhood effects, and the estimated feedback loops - worker quits, effort, strikes, and legal penalties - imply that costs of wage delays are attenuated by neighborhood arrears. We also study a nonlinear case with two stable equilibria: a punctual payment and a late payment equilibrium. The estimates imply that the theoretical conditions for multiple equilibria under symmetric labor market competition are satisfied in our data.

Contract Violations, Neighborhood Effects, and Wage Arrears in Russia

We present a model of neighborhood effects in wage payment delays. Positive feedback arises because each employer’s arrears affect the late payment costs faced by other firms in the same local labor market, resulting in a strategic complementarity in the practice. The model is estimated on panel data for workers and firms in Russia, facilitating identification through the use of a rich set of covariates and fixed effects at the level of the employee, the employer, and the local labor market. We also exploit a policy intervention affecting public sector workers that provides an instrumental variable to estimate the endogenous reaction in the non-public sector. Consistently across specifications, the estimated reaction function displays strongly positive neighborhood effects, and the estimates of four feedback loops – operating through worker quits, effort, strikes, and legal penalties – imply that costs of delays are attenuated by neighborhood arrears. We also study a nonlinear case exhibiting two stable equilibria: a “punctual payment equilibrium” and a “late payment equilibrium.” The estimates imply that the theoretical conditions for multiple equilibria under symmetric local labor market competition are satisfied in our data.

Minireviews: Neighborhood Effects, Disturbance Severity, and Community Stability in Forests

A theoretical framework and conceptual model for temporal stability of forest tree-species composition was developed based on a synthesis of existing studies. The model pertains primarily to time periods of several tree lifetimes (several hundred to a few thousand years) at the neighborhood and stand spatial scales (0.01–10 ha), although a few extensions to the landscape scale are also made. The cusp catastrophe was chosen to illustrate compositional dynamics at the stand level for jack pine, northern hardwood, and white pine forests in the Great Lakes Region of the United States and for tropical rainforests in the northern Amazon basin. The models feature a response surface (degree of dominance by late-successional species) that depends on two variables: type of neighborhood effects of the dominant tree species and severity of disturbances. Neighborhood effects are processes that affect the chance of a species replacing itself at the time of disturbance (they can be positive, neutral, or negative) and are of two types: overstory–undestory effects, such as the presence of advanced reproduction; and disturbance-activated effects, such as serotinous seed rain. Disturbance severity is the proportion of trees killed during a disturbance. Interactions between neighborhood effects and disturbance severity can lead to either punctuated stability (dramatic but infrequent change in composition, in those forests dominated by species with positive neighborhood effects) or succession (continuous change, in those forests dominated by species with neutral-negative neighborhood effects). We propose that neighborhood effects are a major organizing factor in forest dynamics that provide a link across spatial scales between individual trees and disturbance/patch dynamics at the stand and landscape scales.