Efficiency or Competition? A Structural Econometric Analysis of Canada's AWS Auction and the Set‐Aside Provision

In 2008, Industry Canada auctioned 105 MHz of spectrum to a group of bidders that included incumbents and potential new entrants into the Canadian mobile phone market, raising $4.25 billion. In an effort to promote new entry, 40 MHz of spectrum was set‐aside for new entrants. In order to estimate the implicit cost of the set‐aside provision, we estimate the parameters of the bidders' profit function via a maximum match estimator based on the notion of pairwise stability in matches. We find that all telecommunications firms valued both geographic complementarities across auction licenses as well as absolute spectrum. Under a reasonable alternative scenario, our results indicate that the set‐aside led to a total profit loss of approximately 10%.     

Missing millions: undercounting urbanization in India

Population and Environment - The measurement and characterization of urbanization crucially depends upon defining what counts as urban. The government of India estimates that only 31% of the...     

Imagining mobility: the prospective cognition question in migration research

Most migration research is focused on migrant experiences after mobility and settlement. We argue that empirical researchers would benefit from studying how cognitive migration, the narrative imagining of oneself inhabiting a foreign destination prior to the actual physical move, influences migration behaviour. This article notes a gap in our current understanding of the process by which individuals decide to cross international borders and offers an agenda for remedying this. The interdisciplinarity of migration research has not fully extended to social psychology or cognitive social sciences, where a dynamic research agenda has examined human decision-making processes, including prospection and the connections between culture and cognition. The study of socio-cognitive processes in migration decision-making has been largely overlooked because of the after-the-fact nature of data collection and analysis rather than an aversion to these approaches per se. We highlight a number of strategic findings from this diverse field, provide examples of migration scholarship that has benefited from these insights, and raise questions about the sides of migration process that have received insufficient attention. A more nuanced understanding of prospective thinking—imagining potential futures—can shed light on the classic puzzle of why some people move while others in comparable situations do not.     

Promoting Fathers' Engagement With Children: Preventive Interventions for Low‐Income Families

Few programs to enhance fathers' engagement with children have been systematically evaluated, especially for low‐income minority populations. In this study, 289 couples from primarily low‐income Mexican American and European American families were randomly assigned to one of three conditions and followed for 18 months: 16‐week groups for fathers, 16‐week groups for couples, or a 1‐time informational meeting. Compared with families in the low‐dose comparison condition, intervention families showed positive effects on fathers' engagement with their children, couple relationship quality, and children's problem behaviors. Participants in couples' groups showed more consistent, longer term positive effects than those in fathers‐only groups. Intervention effects were similar across family structures, income levels, and ethnicities. Implications of the results for current family policy debates are discussed.     

Patterns of pollinator turnover and increasing diversity associated with urban habitats

The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.     

Influence of Proximity to Kin on Residential Mobility and Destination Choice: Examining Local Movers in Metropolitan Areas

A growing body of research has examined how family dynamics shape residential mobility, highlighting the social—as opposed to economic—drivers of mobility. However, few studies have examined kin ties as both push and pull factors in mobility processes or revealed how the influence of kin ties on mobility varies across sociodemographic groups. Using data on local residential moves from the Panel Study of Income Dynamics (PSID) from 1980 to 2013, we find that location of noncoresident kin influences the likelihood of moving out of the current neighborhood and the selection of a new destination neighborhood. Analyses of out-mobility reveal that parents and young adult children living near each other as well as low-income adult children living near parents are especially deterred from moving. Discrete-choice models of neighborhood selection indicate that movers are particularly drawn to neighborhoods close to aging parents, white and higher-income households tend to move close to parents and children, and lower-income households tend to move close to extended family. Our results highlight the social and economic trade-offs that households face when making residential mobility decisions, which have important implications for broader patterns of inequality in residential attainment.     

Metropolitan Heterogeneity and Minority Neighborhood Attainment: Spatial Assimilation or Place Stratification?

Using geo-referenced data from the Panel Study of Income Dynamics, in conjunction with decennial census data, this research examines metropolitan-area variation in the ability of residentially mobile blacks, Hispanics, and whites to convert their income into two types of neighborhood outcomes-neighborhood racial composition and neighborhood socioeconomic status. For destination tract racial composition, we find strong and near-universal support for the "weak version" of place stratification theory; relative to whites, the effect of individual income on the percent of the destination tract population that is non-Hispanic white is stronger for blacks and Hispanics, but even the highest earning minority group members move to tracts that are "less white" than the tracts that the highest-earning whites move to. In contrast, for moves into neighborhoods characterized by higher levels of average family income, we find substantial heterogeneity across metropolitan areas in minorities' capacity to convert income into neighborhood quality. A slight majority of metropolitan areas evince support for the "strong version" of place stratification theory, in which blacks and Hispanics are less able than whites to convert income into neighborhood socioeconomic status. However, a nontrivial number of metropolitan areas also evince support for spatial assimilation theory, where the highest-earning minorities achieve neighborhood parity with the highest-earning whites. Several metropolitan-area characteristics, including residential segregation, racial and ethnic composition, immigrant population size, poverty rates, and municipal fragmentation, emerge as significant predictors of minority-white differences in neighborhood attainment.     

A critique of arguments supporting disability avoidance

Many prominent bioethicists argue that positive consequences follow from avoiding disability in offspring by preconceptual, preimplantation or prenatal means. This paper critiques two variants of these positions: ‘Open future’ arguments that avoiding disability is in the interest of the persons who will be affected by it if born and ‘non‐person‐affecting’ claims that failures to avoid disability in offspring are wrong for reasons independent of their effect on affected offspring. Difficulties with both person‐affecting and non‐person‐affecting accounts are discussed in support of the charge that these arguments do not show that positive consequences follow from disability avoidance.     

Metropolitan influences on migration into poor and nonpoor neighborhoods

Data from the Panel Study of Income Dynamics and three decennial US censuses are used to examine the influence of metropolitan-area characteristics on black and white households’ propensity to move into poor versus nonpoor neighborhoods. We find that a nontrivial portion of the variance in the odds of moving to a poor rather to a nonpoor neighborhood exists between metropolitan areas. Net of established individual-level predictors of inter-neighborhood migration, black and white households are more likely to move to a poor or extremely poor tract rather than to a nonpoor tract in metropolitan areas containing many poor neighborhoods and a paucity of recently-built housing in nonpoor areas. Blacks are especially likely to move to a poor tract in metropolitan areas characterized by high levels of racial residential segregation and in which poor tracts have a sizeable concentration of blacks. White households are more likely to move to a poor than to a nonpoor tract in metropolitan areas that have comparatively few African Americans.     

Using In Vitro High‐Throughput Screening Data for Predicting Benzo[k]Fluoranthene Human Health Hazards

Today there are more than 80,000 chemicals in commerce and the environment. The potential human health risks are unknown for the vast majority of these chemicals as they lack human health risk assessments, toxicity reference values, and risk screening values. We aim to use computational toxicology and quantitative high‐throughput screening (qHTS) technologies to fill these data gaps, and begin to prioritize these chemicals for additional assessment. In this pilot, we demonstrate how we were able to identify that benzo[k]fluoranthene may induce DNA damage and steatosis using qHTS data and two separate adverse outcome pathways (AOPs). We also demonstrate how bootstrap natural spline‐based meta‐regression can be used to integrate data across multiple assay replicates to generate a concentration–response curve. We used this analysis to calculate an in vitro point of departure of 0.751 μM and risk‐specific in vitro concentrations of 0.29 μM and 0.28 μM for 1:1,000 and 1:10,000 risk, respectively, for DNA damage. Based on the available evidence, and considering that only a single HSD17B4 assay is available, we have low overall confidence in the steatosis hazard identification. This case study suggests that coupling qHTS assays with AOPs and ontologies will facilitate hazard identification. Combining this with quantitative evidence integration methods, such as bootstrap meta‐regression, may allow risk assessors to identify points of departure and risk‐specific internal/in vitro concentrations. These results are sufficient to prioritize the chemicals; however, in the longer term we will need to estimate external doses for risk screening purposes, such as through margin of exposure methods.