Does urbanization affect the seasonal dynamics of bird communities in urban parks?

The environmental factors affecting the spatial dynamics of bird communities in urban parks are well understood, but much less attention has been paid to the seasonal dynamics of bird communities. Since migrant and resident human commensal birds might have contrasting responses to environmental factors of urban parks, we expected different seasonal dynamics among parks. On the other hand, because bird species can have different habitat relationships throughout the year, we also expected different responses of bird richness to environmental variables between breeding and non-breeding seasons. Bird surveys were conducted in 14 small urban parks (1–4 Ha) of Mar del Plata city (Argentina) for one full annual cycle. Bird richness changed between seasons, but bird abundance remained constant. Bird community composition did not vary between seasons, but urban parks near the urban center, with the highest pedestrian traffic and isolation to other green areas had the least seasonal change of composition. During the breeding season, bird richness was negatively affected by the percentage cover of high buildings surrounding the immediate limits of parks, whereas during the non-breeding season bird richness was not related with any environmental variable. Bird composition variation among parks was affected by the distance to the urban center during both seasons. Results showed that urbanization promotes a seasonal homogenization of bird communities in urban parks, probably by affecting the presence of migrant species and promoting the temporal stability of human commensal species.     

Within inequality characteristics and adaptation of immigrants in the United States

Until recently, in works of literature, the assimilation of immigrants had been viewed as an individualistic rather than a community-based process. However, Hatton and Leigh (2011) showed that immigrants integrate to their host country as communities, not as individuals; hence, group characteristics play as much of a role as individual characteristics in terms of adaptation. This paper introduces another dimension to the immigrant adaptation proxies that reflect community-based characteristics. The fundamental assertion of this paper is that inequality can be used as a proxy of adaptation within immigrant groups. Immigrant groups that exhibit income and education distributions similar to those of the natives can be regarded as well-adapted groups, while those who exhibit vastly different distributions should be considered to be groups with limited adaptation. Using the American Community Survey (ACS) 2010 cohort, this paper presents the initial findings of the within-group inequality of immigrants. Then, a cross-sectional regression analysis is employed to analyze the determinants of inequality across these immigrant groups. The results suggest that immigrant community-based characteristics, such as average income, education, and number of years that the immigrants have spent in the US, can indeed explain most of the variation in inequality.     

Assimilation effects beyond the labor market: time allocations of Mexican immigrants to the US

I use the American Time Use Survey from 2003 to 2012 to analyze, from a gender and marital status perspective, how the time Mexican immigrants devote to market work, household production, personal care, and leisure activities compare to the corresponding time allocations of US natives. Furthermore, I estimate the effect of duration of residence in the US on the immigrants overall patterns of time use. Time diary evidence indicates that, upon arrival to the US, Mexican immigrant men devote more time to market work and commuting than comparable non-Hispanic natives, regardless of their marital status. On the other hand, Mexican immigrant women devote the same amount of time to these activities as the non-Hispanic reference groups, irrespective of the marital status. In addition, the trend data show that immigrant men decrease their paid work with years since migration while immigrant women increase it. Estimates indicate that, for married immigrant men there is a tradeoff between market work and household work, whereas for single immigrant men the tradeoff is between market work and leisure. Finally, Mexican immigrant women relinquish mostly passive leisure and sleep time to meet demands of family and market work.     

The increasing happiness of US parents

Previous research suggests that parents may be less happy than non-parents. We critically assess the literature and examine parents’ and non-parents’ happiness-trends using the General Social Survey (N = 42,298) and DDB Lifestyle Survey (N = 75,237). We find that parents are becoming happier over time relative to non-parents, that non-parents’ happiness is declining absolutely, and that estimates of the parental happiness gap are sensitive to the time-period analyzed. These results are consistent across two datasets, most subgroups, and various specifications. Finally, we present evidence that suggests children appear to protect parents against social and economic forces that may be reducing happiness among non-parents.     

A global count of the extreme poor in 2012: data issues,methodology and initial results

The 2014 release of a new set of purchasing power parity (PPP) conversion factors (PPPs) for 2011 has prompted a revision of the World Bank’s international poverty line. In revising the line, we have sought to minimize changes to the real purchasing power of the earlier $1.25 line (in 2005 PPPs), so as to preserve the integrity of the goalposts for international targets such as the Sustainable Development Goals (SDGs) and the World Bank’s twin goals – which were set with respect to that line. In particular, the new line was obtained by inflating the same fifteen national poverty lines – originally used by Ravallion et al. (World Bank Econ. Rev. 23(2): 163–184 2009) to construct the $1.25 line – to 2011 prices in local currency units, and then converting them to US dollars using 2011 PPP conversion factors. With a small approximation, this procedure yields a new international poverty line of $1.90 per person per day. In combination with other changes described in the paper, this revision leads to relatively small changes in global poverty incidence for 2011: from 14.5 % using the old method to 14.1 % using the new method. In 2012, the new reference year for the global count, we find 12.7 % of the world’s population, or 897 million people, are living in extreme poverty. There are changes in the regional composition of poverty, but they are also relatively small. This paper documents methodological decisions taken in the process of updating both the poverty line and the consumption and income distributions at the country level, including issues of inter-temporal and spatial price adjustments. It also describes various caveats and limitations of the approach taken.     

Fundamental accrued capital gains and the measurement of top incomes: an application to Chile

Most previous studies of income inequality have either ignored capital gains or have used taxable realized capital gains to estimate top incomes. Neither of these approaches is fully satisfactory. We apply for the first time a new methodology that allows us to account for fundamental accrued capital gains as part of the top incomes in a theoretically consistent manner. We estimate the shares of the super-rich in Chile showing that accrued capital gains have a large impact on these estimates. Also, the top income shares estimated using fundamental capital gains appear to exhibit a more stable and presumably more plausible time profile than estimates based on capital gains derived from asset market variations.     

Migration to the US and marital mobility

When immigrants enter the US they typically access a marriage market with a larger supply of educated spouses compared to the marriage market in their home countries. Absent any selectivity bias, this access should increase the likelihood that migrants ‘marry-up’ in terms of education. We combine survey data on British and German immigrants in the US with data on natives in Britain and Germany to estimate the causal effect of migration on educational mobility through cross-national marriage. To control for selective mating, we instrument educational attainment using government spending on education in the years each person was of school-age. To control for selective migration, we instrument the migration decision using inflows of immigrants to the US during puberty and early adulthood. We find strong selectivity effects that work against the positive prospects of the US marriage market. All migrants give up spousal education in exchange for US entry and assimilation. Migrant men also give up spousal education because they cannot compete with native men as bread-earners. Migrant women have some advantage in the US marriage market, as they can compete with native women in home production.     

The FARSEEING real-world fall repository: a large-scale collaborative database to collect and share sensor signals from real-world falls

Background

Real-world fall events objectively measured by body-worn sensors can improve the understanding of fall events in older people. However, these events are rare and hence challenging to capture. Therefore, the FARSEEING (FAll Repository for the design of Smart and sElf-adaptive Environments prolonging Independent livinG) consortium and associated partners started to build up a meta-database of real-world falls.

Results

Between January 2012 and December 2015 more than 300 real-world fall events have been recorded. This is currently the largest collection of real-world fall data recorded with inertial sensors. A signal processing and fall verification procedure has been developed and applied to the data. Since the end of 2015, 208 verified real-world fall events are available for analyses. The fall events have been recorded within several studies, with different methods, and in different populations. All sensor signals include at least accelerometer measurements and 58 % additionally include gyroscope and magnetometer measurements. The collection of data is ongoing and open to further partners contributing with fall signals. The FARSEEING consortium also aims to share the collected real-world falls data with other researchers on request.

Conclusions

The FARSEEING meta-database will help to improve the understanding of falls and enable new approaches in fall risk assessment, fall prevention, and fall detection in both aging and disease.

     

On Comparing Alternative Advertising Policies of Pulsation*

In this paper, five alternative advertising policies that belong to the advertising pulsation class are compared analytically for linear and concave response functions using a modified version of the Vidale-Wolfe model. The results of the research show that (1) For both linear and concave response functions, advertising pulsing/maintenance policy dominates advertising pulsing policy but is dominated by the Uniform Advertising Policy. For convex response functions, the order of dominance is reversed. (2) For linear response functions, uniform advertising policy dominates the impulse advertising policy but is dominated by the chattering advertising policy. (3) For concave response functions, uniform advertising policy dominates both the impulse advertising policy and the chattering advertising policy. (4) For convex response functions, chattering advertising policy dominates both the advertising pulsing policy and the impulse advertising policy. The Vidale-Wolfe model is estimated using the well-known Lydia Pinkham data. Optimality analysis shows that the company was overadvertising about half of the time studied. Overadvertising seems to have produced appreciable gain in sales and created significant barriers to competitive entry at a little cost in terms of foregone profits.