Behind at the Starting Line: Poverty Among Hispanic Infants

In this brief, authors Daniel Lichter, Scott Sanders, and Kenneth Johnson examine the economic circumstances of Hispanic infants using the Census Bureau’s American Community Survey annual microdata files from 2006 through 2010. They report that a disproportionate share of Hispanic infants start life’s race behind the starting line, poor and disadvantaged—an important finding because the proportion of all U.S. births that are Hispanic is growing rapidly. The poverty risk is especially high among rural Hispanic infants and those in new destinations. Despite higher poverty risks, Hispanic infants receive less governmental assistance. High Hispanic infant poverty has immediate and long-term consequences for infants and the nation. Failing to invest in families and children now has long-term consequences because early childhood poverty tends to set into motion a series of lifecycle disadvantages (such as insufficient parenting, bad neighborhoods, underfunded schools, and poor health care) that greatly increases the likelihood of poverty in adulthood. The authors conclude that whether today’s Hispanic children will assimilate into America’s economic mainstream is an open question, but the Hispanic infants who will help reshape America’s future require public policy attention now

Monitoring, Motivation and Management: The Determinants of Opportunistic Behavior in a Field Experiment

Economic models of incentives in employment relationships are based on a specific theory of motivation. Employees are 'rational cheaters,' who anticipate the consequences of their actions and shirk when the perceived marginal benefit exceeds the marginal cost. Managers respond to this decision calculus by implementing monitoring and incentive pay practices that lessen the attraction of shirking. This 'rational cheater model' is not the only model of opportunistic behavior, and indeed is viewed skeptically by human resource practitioners and by many non-economists who study employment relationships. We investigate the 'rational cheater model' using data from a double-blind field experiment that allows us to observe the effect of experimentally-induced variations in monitoring on employee opportunism. The experiment is unique in that it occurs in the context of an ongoing employment relationship, i.e., with the firm's employees producing output as usual under the supervision of their front-line managers. The results indicate that a significant fraction of employees behave roughly in ccordance with the 'rational cheater model.' We also find, however, that a substantial proportion of employees do not respond to manipulations in the monitoring rate. This heterogeneity is related to employee assessments about their general treatment by the emp loyer.

Social Work Concerns Related to Peace and People Oriented Development in the International Context

It is the thesis of this paper that the social work profession along with other human service professions has the potential of making a vital contribution in promoting peace and people oriented development and that the ultimate test of the profession\u27s contribution to individuals, families, and communities in varying contexts is the ensuring of human survival and the enhancing of the quality of life for all people

Efficient Yao Graph Construction

Yao graphs are geometric spanners that connect each point of a given point set to its nearest neighbor in each of k cones drawn around it. Yao graphs were introduced to construct minimum spanning trees in d dimensional spaces. Moreover, they are used for instance in topology control in wireless networks. An optimal ?(n log n)-time algorithm to construct Yao graphs for a given point set has been proposed in the literature but - to the best of our knowledge - never been implemented. Instead, algorithms with a quadratic complexity are used in popular packages to construct these graphs. In this paper we present the first implementation of the optimal Yao graph algorithm. We engineer the data structures required to achieve the ?(n log n) time bound and detail algorithmic adaptations necessary to take the original algorithm from theory to practice. We propose a priority queue data structure that separates static and dynamic events and might be of independent interest for other sweepline algorithms. Additionally, we propose a new Yao graph algorithm based on a uniform grid data structure that performs well for medium-sized inputs. We evaluate our implementations on a wide variety of synthetic and real-world datasets and show that our implementation outperforms current publicly available implementations by at least an order of magnitude

A Sweep-Plane Algorithm for Calculating the Isolation of Mountains

One established metric to classify the significance of a mountain peak is its isolation. It specifies the distance between a peak and the closest point of higher elevation. Peaks with high isolation dominate their surroundings and provide a nice view from the top. With the availability of worldwide Digital Elevation Models (DEMs), the isolation of all mountain peaks can be computed automatically. Previous algorithms run in worst case time that is quadratic in the input size. We present a novel sweep-plane algorithm that runs in time ?(nlog n+pT_NN) where n is the input size, p the number of considered peaks and T_NN the time for a 2D nearest-neighbor query in an appropriate geometric search tree. We refine this to a two-level approach that has high locality and good parallel scalability. Our implementation reduces the time for calculating the isolation of every peak on Earth from hours to minutes while improving precision