The Effects of Multitasking on Operations Scheduling

This study considers a typical scheduling environment that is influenced by the behavioral phenomenon of multitasking. Under multitasking, the processing of a selected job suffers from interruption by other jobs that are available but unfinished. This situation arises in a wide variety of applications; for example, administration, manufacturing, and process and project management. Several classical solution methods for scheduling problems no longer apply in the presence of multitasking. The solvability of any scheduling problem under multitasking is no easier than that of the corresponding classical problem. We develop optimal algorithms for some fundamental and practical single machine scheduling problems with multitasking. For other problems, we show that they are computationally intractable, even though in some cases the corresponding problem in classical scheduling is efficiently solvable. We also study the cost increase and value gained due to multitasking. This analysis informs companies about how much it would be worthwhile to invest in measures to reduce or encourage multitasking.     

Consumption Dynamics During Recessions

Are there times when durable spending is less responsive to economic stimulus? We argue that aggregate durable expenditures respond more sluggishly to economic shocks during recessions because microeconomic frictions lead to declines in the frequency of households' durable adjustment. We show this by first using indirect inference to estimate a heterogeneous agent incomplete markets model with fixed costs of durable adjustment to match consumption dynamics in PSID microdata. We then show that aggregating this model delivers an extremely procyclical Impulse Response Function (IRF) of durable spending to aggregate shocks. For example, the response of durable spending to an income shock in 1999 is estimated to be almost twice as large as if it occurred in 2009. This procyclical IRF holds in response to standard business cycle shocks as well as in response to various policy shocks, and it is robust to general equilibrium. After estimating this robust theoretical implication of micro frictions, we provide additional direct empirical evidence for its importance using both cross‐sectional and time‐series data.     

Abuse of elderly male client: efforts and experiences in rural and urban adult protective services

Elder abuse has not been viewed as seriously as child abuse because of the emotional sensibilities attached to child abuse. Although elder abuse is experienced disproportionately by women, men also are in need of protection and engagement. An important factor for understanding the work with elderly men is the social construction of manhood. Both urban and rural settings recognize this as a significant starting point to engage men in services. This paper describes the efforts in both rural and urban Adult Protective Service agencies to identify and work with abused elderly men from a strengths and solution-focused perspective.     

Environmental changes to increase physical activity: perceptions of older urban ethnic-minority women

Despite the numerous benefits of physical activity, older adults continue to be more sedentary than their younger counterparts, and sedentary behavior is more prevalent among older racial and ethnic minorities than among Whites. This study used the nominal group technique (NGT) to examine participants' perceptions of what neighborhood environmental changes would encourage greater physical activity for older African American and Hispanic women. Participants age 50-75 years were recruited from 2 urban community health clinics. Nine NGT sessions (45 participants) were conducted. The women were asked what changes in their neighborhood environment would encourage them to become more physically active. Responses to the research question were tabulated, and qualitative analysis was used to identify themes and categories. Major categories were physical environment changes, safety, and activities/social support. Although the physical environment received the greatest number of points, concerns for personal safety cut across categories. Participants indicated the need for more facilities in which to be active.     

Maintenance of skilled performance with age: a descriptive examination of professional golfers

Demographic studies indicate a remarkable aging trend in North America. An accurate profile of the decline in physical and cognitive capabilities over time is essential to our understanding of the aging process. This study examined the maintenance of skilled performance across the careers of 96 professional golfers. Data were collected on scoring average, driving distance, driving accuracy, greens in regulation, putts per round, and number of competitive rounds played using online data archives. Analyses indicate that performance in this activity can be maintained to a greater extent than in activities relying on biologically constrained abilities. Although the generalizability of these results to "normal" aging populations is not known, they suggest that acquired skills can be maintained to a large extent in the face of advancing age.     

Hard thresholding regression

In this paper, we propose the hard thresholding regression (HTR) for estimating high‐dimensional sparse linear regression models. HTR uses a two‐stage convex algorithm to approximate the ?₀‐penalized regression: The first stage calculates a coarse initial estimator, and the second stage identifies the oracle estimator by borrowing information from the first one. Theoretically, the HTR estimator achieves the strong oracle property over a wide range of regularization parameters. Numerical examples and a real data example lend further support to our proposed methodology.     

Walking a tightrope: reflections on police gatekeeping roles in suicide research in Ghana

Engaging non-conventional gatekeepers such as the police presents both promises and perils. Although studies have relied on police data for researching suicide and other sensitive topics in Africa, there is a paucity of literature that explores or reflects on police gatekeeping and its research implications. This paper presents authors’ reflections on police gatekeeping in a qualitative suicide study in Accra, Ghana. The main observation is that the process was double-edged. On the one hand, it led to field delays and costs, (mis)apprehensions and positionality problems, and trust building challenges. On the other hand, it vouched for research(er) credibility, provided therapeutic openings, and facilitated the viability of research with the suicide bereaved. Sensitivity to research context, sensitising the police, and reinforcing ‘therapeutic-research discourse’ with participants, are recommended means for aligning participants’ goals to research goals and for achieving therapeutic disclosures.     

Young people’s perceptions of power and influence as a basis for understanding contemporary citizenship

Persistent simplistic binary discourses of young people’s citizenship portray them either as civically deficit and disengaged citizens or the creators of new democratic modes and approaches. This paper draws on field research with two groups of young people in Australia to better recognise the nuance of young people’s experiences of citizenship, power and influence. The study investigated the extent to which different groups of young people believe that they have the power to influence society; the ways in which they seek this influence; the current barriers to their influence; and what would enable them to have greater influence. Our analysis in this paper draws on Lukes’ concepts of power [2005. Power: A Radical View. 2nd ed. London: Palgrave Macmillan] and Arvanitakis’ framework of citizenship engagement and empowerment [in Arvanitakis, J., and E. Sidoti. 2011. “The Politics of Change: Where to for Young People and Politics.” In Their Own Hands: Can Young People Change Australia?, edited by L. Walsh and R. Black, 11–20. Melbourne: ACER Press], but also builds on an emerging scholarship concerned with the geographic dimensions of young people’s citizenship engagement and action, as well as with the affective, relational and temporal dimensions of this engagement and action. Our findings suggest that power works in different ways to both constrain and liberate young people as citizens – sometimes at the same time. The paper concludes with an argument for the continuing need to understand young people’s lived and located experiences of engagement, power and influence in more nuanced and sophisticated ways. This includes reframing the discussion about young people’s experiences in terms of the nature of their democratic engagement and action rather than simply their citizenship.