Stochastic and Intransitive Behavior in a State-Preference Model of Asset Choice*

Most models of investor behavior assume a time-state independent utility function and result in a deterministic solution where a given set of inputs uniquely specifies the decision. In contrast, a state preference model using a time-state dependent utility function is derived in this paper. The model allows the investment choice decision to be analyzed in a game theoretic context. The general solution is a mixed strategy which allows for a probabilistic interpretation of the decision. The approach presented in this paper can accommodate anomalies such as intransitivity of preference and satisficing as rational behavior. An example of a possible implementation is given along with interpretations of the outcomes.     

Scheduling in a Management Context: Uncertain Processing Times and Non-Regular Performance Measures*

Decision makers often face scheduling problems in which processing times are not known with certainty. Non-regular performance measures, in which both earliness and tardiness are penalized, are also becoming more common in both manufacturing and service operations. We model a managerial environment with task processing times (which include sequenceindependent set-up times) prescribed by three-parameter lognormal distributions. Upon completion, each task derives a reward given by a particular piecewise-linear reward function. The objective is to select a sequence of tasks maximizing the expected total reward. The relative generality of the problem renders many enumerative methods inapplicable or computationally intractable. To overcome such difficulties we develop efficient priorityinduced construction (PIC) heuristics which build up a complete schedule by inserting tasks (singly from a list) into a partial sequence of tasks. In each partial and complete sequence a period of idle time is permitted prior to the first task. Performance on realistic-sized problems is very encouraging, with cost penalties averaging less than one percent.     

Dynamics of Asset Poverty in South Korea

Studies of economic insecurity tend to focus on changes in incomes and transitions in and out of income poverty. Yet family economic conditions are shaped by more than just income. Levels of assets and wealth, and changes in these over time also play a role. To identify which groups of the poor have been structurally trapped in poverty over time, using the Korean Welfare Panel Study, we examined the dynamics of asset poverty from 2005 to 2014. We defined three asset poverty lines by operationalizing assets as resources for either future consumption or development. Findings show that asset poverty experience in a previous year significantly increased the probability to incur asset poverty by 5–12% for all analysis samples. In addition, the probability of incurring asset poverty decreased with home ownership, higher disposable income, and greater diversification of the household portfolio. Our findings suggest that the asset poor are likely to fall into structural and persistent poverty over time, and an asset-building approach is needed to improve the asset poverty status of households in South Korea.

     

Income Inequality across the Rural-Urban Continuum in the United States, 1970–2016*

The growth in macro-level income inequality in the United States is well established, but less is known about patterns of inequality at subnational scales and how they vary between and within rural and urban localities. Using data from the Decennial Census and American Community Survey, we produce estimates of within-county income inequality from 1970 to 2016 and analyze differences in inequality levels, the persistence of high (low) inequality, and populations' exposure to high (low) inequality across the rural-urban continuum. We find that income inequality has historically been higher in non-metropolitan than metropolitan counties, but inequality levels converged by 2016 due to growing inequality in metropolitan counties. Additionally, levels of inequality were generally persistent within counties over time, except that counties characterized by low inequality in 1970 were unlikely to remain as such in 2016. Third, non-trivial shares of the metropolitan population resided in low-inequality contexts in 1970, but virtually none of the U.S. population resided in such places by 2016. Residence in high-inequality counties is normative in rural and urban America. This statistical analysis provides an updated portrait of income inequality across the rural-urban continuum, and should spur additional research on stratification in rural America during an era of growing inequality.     

Terms of engagement: Facebook and Twitter use among nonprofit human service organizations

This study uses Lovejoy and Saxton's (2012) hierarchy of engagement to analyze how nonprofit human service organizations use Facebook and Twitter to engage stakeholders. Their framework has not been applied to this nonprofit subgroup, and most previous scholarship on this topic focuses on just one platform. We also contribute by drawing on organizational theory to better understand variation in the modes of engagement organizations emphasize. Based on our analysis, we add new subcategories to the hierarchy of engagement. In addition, we find that compared to other nonprofit subgroups examined in previous research, the organizations in our sample placed a greater emphasis on using social media messages to ask stakeholders to take action. We report only modest variations in how organizations were using Facebook and Twitter. Finally, according to our results, resource dependence and stewardship theories help explain the modes of engagement organizations prioritize.     

How School Contexts Shape the Relations Among Adolescents’ Beliefs,Peer Victimization,and Depressive Symptoms

The present research examined how school contexts shape the extent to which beliefs about the potential for change (implicit theories) interact with social adversity to predict depressive symptoms. A preregistered multilevel regression analysis using data from 6,237 ninth‐grade adolescents in 25 U.S. high schools showed a three‐way interaction: Implicit theories moderated the associations between victimization and depressive symptoms only in schools with high levels of school‐level victimization, but not in schools with low victimization levels. In high‐victimization schools, adolescents who believed that people cannot change (an entity theory of personality) were more depressed when they were victimized more frequently. Thus, the mental health correlates of adolescents’ implicit theories depend on both personal experiences and the norms in the context.     

Recent developments in school social control

In the U.S., decisions regarding social control are increasingly modeled on two dominant institutions: the criminal justice and medical/healthcare systems. Sociologists and other scholars refer to this adoption of legal and/or medical terminology and technologies as criminalization and medicalization. These models of social control are particular evident in how America defines and manages child behavior. Public schools borrow from both the criminal justice and medical systems as part of the routine educational setting. In this article, I provide the first synthesis and review of the school criminalization and medicalization literatures. In doing so, I argue that criminalized school social controls provide harsh, repressive responses to student misbehavior, while medicalized school social controls provide rehabilitative and restitutive responses. Given these fundamentally different approaches to student behavior, I argue that the disproportionate use of criminalized and medicalized social control across racial/ethnic groups and children from different socioeconomic backgrounds entrenches inequalities and functions to channel racial/ethnic minorities and poor children into the school‐to‐prison pipeline while keeping socially advantaged children in school and away from the problems associated with criminalized social control.     

Policy-induced Innovation in Sub-Saharan African Agriculture: A Multilateral Malmquist Productivity Index Approach

To meet the [African] crisis one must turn to agricultural-led growth. But, based on historical experience, an agricultural-led strategy must be framed in no less than a twenty-year horizon and must entail a combination of technological innovation, policy reform, and institutional restructuring because each, by itself, is limited. (Eicher, 1989)     

A Decision Model for the Robot Selection Problem Using Robust Regression*

Industrial robots are increasingly used by many manufacturing firms. The number of robot manufacturers has also increased with many of these firms now offering a wide range of models. A potential user is thus faced with many options in both performance and cost. This paper proposes a decision model for the robot selection problem. The proposed model uses robust regression to identify, based on manufacturers' specifications, the robots that are the better performers for a given cost. Robust regression is used because it identifies and is resistant to the effects of outlying observations, key components in the proposed model. The robots selected by the model become candidates for testing to verify manufacturers' specifications. The model is tested on a real data set and an example is presented.     

Solution Procedures for the Lot-Streaming Problem

Lot streaming is the process of splitting a job into sublots so its operations can be overlapped and its progress accelerated. We present a computationally efficient procedure for solving the m-machine, two-sublot problem, and we discuss the bottleneck insights that emerge from the analysis. We also examine heuristic approaches for more than two sublots and discuss computational results for these procedures.