On the asymptotic bias of OLS in dynamic regression models with autocorrelated errors

It is well-known that Ordinary Least Squares (OLS) yields inconsistent estimates if applied to a regression equation with lagged dependent variables and correlated errors. Bias expressions which appear in the literature usually assume the exogenous variables to be non-stochastic. Due to this assumption the numerical sizes of these expressions cannot be determined. Further, the analysis is mostly restricted to very simple models. In this paper the problem of calculating the asymptotic bias of OLS is generalized to stationary dynamic regression models, where the errors follow a stationary ARMA process. A general bias expression is derived and a method is introduced by which its actual size can be computed numerically.     

WORKING "OVER-TIME":

This article examines the reasons working-class retirees give for their continued labor activity and discusses these in relation to the present socioeconomic situation. Through the use of primary qualitative data supplemented by others' empirical work, it is argued that working-class retirees engage in labor because they lack the economic resources to survive, desire to maintain their previous status, and experience threats to the status of their families and communities. Their experience differs from that commonly anticipated by society. Their labor is an important component of the U.S. economic recovery in recent years. Working-class retirees' labor involvement thus is not a solution, but a problem.     

Summer Engagement for At-Risk Youth: Preliminary Outcomes from the New York State Workforce Development Study

The goal of engaging high-risk youth in pro-social activities is to reduce involvement in the criminal justice system and create experiences that increase the youth’s chance of success in education and employment in the future. However, the literature does not support this assumption. The current study looks at the Summer Youth Engagement Program in New York State (NYSYEP). NYSYEP attempts to engage youth in a variety of pro-social activities including employment; education programs; organized recreation programs; and, volunteer work or community service. The hypothesis for the study was that youth who were engaged in pro-social activities would be more likely to be rearrested than youth who were not engaged. The number of hours of youth engagement was found to reduce the odds of being rearrested, but by only 2 %.     

Designing a campus support program for foster care alumni: Preliminary evidence for a strengths framework

Campus support programs for foster care alumni (FCA) have emerged in an attempt to improve higher education outcomes for former foster youth. However, these programs have little empirical or theoretical literature to guide their development. We present a case study of a newly developed campus support program for FCA which utilizes a strengths perspective. We analyze quantitative and qualitative data collected before and during the first two years of program operation to explore whether a strengths perspective can be successfully applied to the unique needs of FCA in higher education. Results reveal that the strengths perspective has potential and identifies three areas in which this approach appears to effectively intersect with challenges faced by FCA, a) promoting positive identities as survivors, b) respecting autonomy, and c) mobilizing assets of resilience, perseverance, and community. We discuss the benefits and challenges of helping students address these issues. Our findings also reveal that the strengths perspective is not redundant with traditional higher education retention models, and in the three areas identified, is diametrically opposed to the students' previous experiences with the foster care system.     

Sibling Family Practices: Guidelines for Healthy Boundaries

A questionnaire was given to 500 mental health and child welfare professionals asking for maximum acceptable ages for siblings to engage jointly in certain family practices related to hygiene, affection, and privacy. A large proportion of respondents felt it was never acceptable for siblings to take showers together (40%), kiss on the mouth (37%), or toilet together (32%). Some significant differences occurred based on the gender of the older sibling within sets of same gender or mixed gender pairs, with older brothers being acceptable up to lower ages than older sisters. The effects of child abuse, age, race, and the amount of education on the respondents' answers are investigated. The limitations of the age guidelines are discussed.     

Post-lesbian? Not yet

Though some may encourage us to consider ourselves in a 'post-lesbian' era, political cultural and academic realities suggest something quite different. Analyzing specific cases in all three of these arenas can strengthen a resolve to insist on the preservation of both the term and concept embodied by 'lesbian.' Finally, this essay suggests several areas open for future investigation by scholars and activists alike.     

Sample size calculation for the Power Model for dose proportionality studies

There are several approaches to assess or demonstrate pharmacokinetic dose proportionality. One statistical method is the traditional ANOVA model, where dose proportionality is evaluated using the bioequivalence limits. A more informative method is the mixed effects Power Model, where dose proportionality is assessed using a decision rule for the estimated slope. Here we propose analytical derivations of sample sizes for various designs (including crossover, incomplete block and parallel group designs) to be analysed according to the Power Model.     

URban Biotopes of Aotearoa New Zealand (URBANZ) (I): composition and diversity of temperate urban lawns in Christchurch

Christchurch urban lawns are dominated by non-native grasses and forbs. However, we document considerable plant diversity; the total number of species encountered in our 327 sampled lawns was 127, although 80 species occurred in <2% of lawns. Seven distinct lawn communities were identified by Two-Way INdicator SPecies ANalysis using occurrence of 47 species that occurred in > 2% of lawns. Our ability to explain variation in species composition was surprisingly good and indicates intensity of lawn maintenance such as frequency of mowing, irrigation, fertiliser, and herbicide use and whether clippings are removed or not plays the major role. Species richness significantly declines with an increase in total area of contiguous lawn, leaf litter cover, the presence of grass clippings, and on loamy soil. Hence, park lawns with coarser management had lower species richness than residential lawns. Native species were more prevalent in well tended residential lawns, where more frequent mowing and removal of clippings or litter build-up diminishes shoot competition or shading. There is tremendous potential for more native species in New Zealand lawns which would contribute substantially to the conservation of endangered lowland herbaceous flora.