Parallel Subjective Well-Being and Choice Experiment Evaluation of Ecosystem Services: Marine and Forest Reserves in Coastal Oregon,USA

Social Indicators Research - There is significant policy and research interest in (a) ecosystem services as a framework for understanding the benefits humans receive from natural systems and (b)...     

MULTIPLE ECONOMIES AND YOUTH LIVELIHOOD

In this paper we present a model of multiple economic spheres in order to understand and explain the income-generating activities of young people. These spheres include the formal sector, the informal waged sector, the informal non-waged sector, the welfare sector and the criminal sector. We conclude that, due to changes in the labour market that affect them in particular ways, young people are engaged in a diverse range of activities within and across each economic sphere.     

A Model for Resource Constrained Production and Inventory Management

We present a general model for multi-item production and inventory management problems that include a resource restriction. The decision variables in the model can take on a variety of interpretations, but will typically represent cycle times, production batch sizes, number of production runs, or order quantities for each item. We consider environments where item demand rates are approximately constant and performing an activity such as producing a batch of a product or placing an order results in the consumption of a scarceresource that is shared among the items. Some examples of shared resources include limited machine capacity, a restriction on the amount of money that can be tied up in stock, orlimited storage capacity. We focus on the case where the decision variables must be integer valued or selected from a discrete set of choices, such as when an integer number of production runs is desired for each item, or in order quantity problems where the items come in pack sizes containing more than one unit and, therefore, the order quantities must be an integer multiple of the pack sizes. We develop a heuristic and a branch and bound algorithm for solving the problem. The branch and bound algorithm includes reoptimization procedures and the heuristic to improve its performance. Computational testing indicates that the algorithms are effective for solving the general model.     

Migrant fertility in Ghana: selection versus adaptation and disruption as causal mechanisms

The aim of the study presented in this paper is to disentangle the roles of three mechanisms -- selection, adaptation, and disruption -- in influencing migrant fertility in Ghana. Using data from the 1998 Ghana Demographic and Health Survey, we fit Poisson and sequential logit regression models to discern the effects of the above mechanisms on cumulative fertility and annual probabilities of birth. Characteristics of migrants from four types of migration stream are examined and compared with those of non-migrants at origin and destination. We find substantial support for the selection hypothesis among both rural-urban and urban-rural migrants. Disruption is evident only in the fertility timing of second and higher-order births in Ghana. Our finding that migrants bear children at about the same rates as the natives at destination implies that the growth rate of cities will slow down quickly and that the rural population will continue to have high fertility. Thus to achieve a reduction in the national fertility level, family planning activities need to be directed towards rural areas.     

Generation Status,Social Capital,and the Routes Out of High School

This study investigates immigrant-native differences in the activities of adolescents 2 years after their sophomore year of high school. We employ longitudinal data for the modeling of duration, nativity and generation differences in education and employment activities during late adolescence. We ask if the same human and social capital characteristics employed as explanations for nativity differences in achievement are predictive of high school participation versus other activities such as labor force participation within a cohort of adolescents. Despite their lower levels of human capital and lower previous academic performance, recent immigrants who arrive in the United States as adolescents are more likely than those who arrive earlier or those born in the United States to persevere in high school. Access to familial social capital and attitudinal measures help explain some of this effect. As for those who do leave school early, socioeconomic status and language background play a role in the activities respondents pursue. While recent immigrants are more likely to persevere in high school, once they leave they are no more likely to pursue additional education than their U.S. born counterparts.     

Horizontal Hostility; Relations Between Similar Minority Groups

Two studies were conducted to examine the relations between similar minority groups. We predicted that minority group members would show horizontal hostility, a form of prejudice, against members of a similar, but more mainstream, minority group. The results of both studies confirmed this hypothesis. In Study 1, members of 3 Jewish congregations (reform, conservative, orthodox) showed prejudice against a member of a similar but slightly more secular congregation. In Study 2, members of a college varsity soccer team showed prejudice against junior varsity players. We conclude by suggesting that horizontal hostility is the result of social changes since Allport (1954) wrote The Nature of Prejudice. Members of minority groups value their minority social identity, even when the group is stigmatized. The positive value of minority social identity causes group members to look down on members of similar, more mainstream groups.     

Testing for Regime Switching

We analyze use of a quasi‐likelihood ratio statistic for a mixture model to test the null hypothesis of one regime versus the alternative of two regimes in a Markov regime‐switching context. This test exploits mixture properties implied by the regime‐switching process, but ignores certain implied serial correlation properties. When formulated in the natural way, the setting is nonstandard, involving nuisance parameters on the boundary of the parameter space, nuisance parameters identified only under the alternative, or approximations using derivatives higher than second order. We exploit recent advances by Andrews (2001) and contribute to the literature by extending the scope of mixture models, obtaining asymptotic null distributions different from those in the literature. We further provide critical values for popular models or bounds for tail probabilities that are useful in constructing conservative critical values for regime‐switching tests. We compare the size and power of our statistics to other useful tests for regime switching via Monte Carlo methods and find relatively good performance. We apply our methods to reexamine the classic cartel study of Porter (1983) and reaffirm Porter's findings.