Habitat selection by an avian top predator in the tropical megacity of Delhi: human activities and socio-religious practices as prey-facilitating tools

Research in urban ecology is growing rapidly in response to the exponential growth of the urban environment. However, few studies have focused on tropical megacities, and on the interplay between predators’ habitat selection and human socio-economic aspects, which may mediate their resilience and coexistence with humans. We examined mechanisms of breeding habitat selection by a synanthropic raptor, the Black Kite Milvus migrans, in Delhi (India) where kites mainly subsist on: (1) human refuse and its associated prey-fauna, and (2) ritualised feeding of kites, particularly practised by Muslims. We used mixed effects models to test the effect of urban habitat configuration and human practices on habitat selection, site occupancy and breeding success. Kite habitat decisions, territory occupancy and breeding success were tightly enmeshed with human activities: kites preferred areas with high human density, poor waste management and a road configuration that facilitated better access to resources provided by humans, in particular to Muslim colonies that provided ritual subsidies. Furthermore, kites bred at ‘clean’ sites with less human refuse only when close to Muslim colonies, suggesting that the proximity to ritual-feeding sites modulated the suitability of other habitats. Rather than a nuisance to avoid, as previously portrayed, humans were a keenly-targeted foraging resource, which tied a predator’s distribution to human activities, politics, history, socio-economics and urban planning at multiple spatio-temporal scales. Many synurbic species may exploit humans in more subtle and direct ways than was previously assumed, but uncovering them will require greater integration of human socio-cultural estimates in urban ecological research.

     

An Economic Model of Friendship: Homophily,Minorities, and Segregation

We develop a model of friendship formation that sheds light on segregation patterns observed in social and economic networks. Individuals have types and see type‐dependent benefits from friendships. We examine the properties of a steady‐state equilibrium of a matching process of friendship formation. We use the model to understand three empirical patterns of friendship formation: (i) larger groups tend to form more same‐type ties and fewer other‐type ties than small groups, (ii) larger groups form more ties per capita, and (iii) all groups are biased towards same‐type relative to demographics, with the most extreme bias coming from middle‐sized groups. We show how these empirical observations can be generated by biases in preferences and biases in meetings. We also illustrate some welfare implications of the model.     

Unconditional Quantile Regressions

We propose a new regression method to evaluate the impact of changes in the distribution of the explanatory variables on quantiles of the unconditional (marginal) distribution of an outcome variable. The proposed method consists of running a regression of the (recentered) influence function (RIF) of the unconditional quantile on the explanatory variables. The influence function, a widely used tool in robust estimation, is easily computed for quantiles, as well as for other distributional statistics. Our approach, thus, can be readily generalized to other distributional statistics.     

生态文明的未来:马克思和无为生态

工业革命以来,自然生态遭受巨大破坏,各种环境问题大量出现.西方传统经济学思想对此负有不可推卸的责任.与之相反,中国传统文化中主张无为而治的无为思想,更能与马克思的思想相契合,因为,它有利于保持生态系统的平衡,促进人与自然的和谐共处以及经济的可持续发展.     

The Role of Community in Migration Dynamics

Abstract. In this paper, I have presented a theoretical model that investigates the observable hysteresis process in migration dynamics. In the model the migration choice depends not only on wage differential, but also on a U‐shaped benefit function of a community of homogenous ethnic individuals, according to the ‘theory of clubs’. The results, based on real option theory, explain that observable ‘jumps’ in migration flows could depend not only on exogenous shocks, but also on two endogenous variables: the number of coordinated immigrants and the dimension of the community. Indeed, migration choice is delayed until a critical mass of immigrants is reached and possible rigidities of optimal district size could magnify this hysteresis process.     

Estimating Age: College Males Versus Convicted Male Child Sex Offenders

Two samples, male college students and convicted male child sex offenders, are compared on their abilities to accurately estimate the age group of a series of photographs of a sole female ranging in age from 11 to 29. Both samples tend to overestimate the age group of the subject photos, and no significant difference was found between college students and convicted child sex offenders in their ability to estimate the age of females. Both groups are compared demographically, and only limited differences were found. The implications are discussed in regard to theory and prevention of child sexual abuse.     

When Bourgeois Utopias Meet Gentrification: Community and Diversity in a New Urbanist Neighborhood*

Abstract

Scholars have recently begun to explore how social and politically liberal gentrifiers make sense of the classed and racial inequalities linked to gentrification. In this article I ask how residents of one new urbanist “bourgeois utopia”—the Mueller Development in Austin, Texas—experience and give meaning to their neighborhood in a context of gentrification. Drawing on 31 in-depth interviews I explain how new urbanism has reimagined and marketed “diversity” and “community” to middle-class and wealthy consumers and provides these to affluent people as neighborhood amenities. I show how residents draw on diversity ideology and multicultural capital to neutralize what they see as their neighborhood’s role in gentrification. In doing so this article adds to our theoretical understanding of how contemporary urban development exploits pursuits for the social good as rhetorical tools to assuage privileged guilt while promoting profitable enterprises.     

Using the Residual White Noise Autoregressive Order Determination Criterion to Identify Unit Roots in Arima Models

We present a simplified form of a univariate identification approach for time series models based on the residual white noise autoregressive order determination criterion and linear estimation methods. We also show how the procedure can be used to identify the degree of differencing necessary to induce stationarity in data. The performance of this approach is also contrasted with Portmanteau tests for detection of white noise residuals and with Dickey-Fuller and Bayesian procedures for detection of unit roots. Simulated and economic data are used to demonstrate the capabilities of the modified approach.     

War is where the hearth is: gendered labor and the everyday reproduction of the geopolitical in the army reserves

The feminized imaginary of “home and hearth” has long been central to the notion of soldiering as masculinist protection. Soldiering and war are not only materialized by gendered imaginaries of home and hearth though, but through everyday labors enacted within the home. Focusing on in-depth qualitative research with women partners and spouses of British Army reservists, we examine how women’s everyday domestic and emotional labor enables reservists to serve, constituting “hearth and home” as a site through which war is made possible. As reservists – who are still overwhelmingly heterosexual men – become increasingly called upon by the state, one must consider how the changing nature of the Army’s procurement of soldiers is also changing demands on women’s labor. Feminist IPE scholars have shown broader trends in the outsourcing of labor to women and its privatization. Our research similarly underscores the significance of everyday gendered labor to the geopolitical. Moreover, we highlight the fragility of military power, given that women can withdraw their labor at any time. The article concludes that paying attention to women’s everyday labor in the home facilitates greater understanding of one of the key sites through which war is both materialized and challenged.