The foundations of decision theory: An intuitive,operational approach with mathematical extensions

A new axiomatic basis for the foundations of decision theory is introduced and its mathematical development outlined. The system combines direct intuitive operational appeal with considerable structural flexibility in the resulting mathematical framework.     

Aging With Rising Risk: Have Older Households Experienced Faster-Growing Risk Exposure Than Younger Ones Since the 1990s?

Financial markets have been characterized by boom and bust cycles since the 1980s, while the responsibility for managing retirement wealth has increasingly shifted onto individual households at the same time. Policy makers and experts have expressed concern over rising risk exposure among older householders, who appear to be increasingly exposed to the growing financial risks just as they near retirement. We consider household data from the Federal Reserve’s Survey of Consumer Finances from 1989 to 2010 to analyze the correlation between age and risk exposure. We test whether older householders’ risk exposure has indeed grown over time, whether it has increased more than that of younger householders, whether changes in the demographic composition of older householders have contributed to older households’ rising risk exposure, and the degree to which increases in risk exposure can be traced to a growing concentration of household assets held in stocks and housing and to rising householder indebtedness. Our results indicate that risk exposure has grown more for older householders than for younger ones, that demographic changes among older householders have contributed to additional increases in older householders’ risk exposure, and that the growth of older householders’ risk exposure is driven more by rising risky asset concentration and less by greater indebtedness.     

Let's stay close: An examination of the effects of imagined contact on behavior toward children with disability

In line with current developments in indirect intergroup contact literature, we conducted a field study using the imagined contact paradigm among high-status (Italian children) and low-status (children with foreign origins) group members (N = 122; 53 females, mean age = 7.52 years). The experiment aimed to improve attitudes and behavior toward a different low-status group, children with disability. To assess behavior, we focused on an objective measure that captures the physical distance between participants and a child with disability over the course of a five-minute interaction (i.e., while playing together). Results from a 3-week intervention revealed that in the case of high-status children imagined contact, relative to a no-intervention control condition, improved outgroup attitudes and behavior, and strengthened helping and contact intentions. These effects however did not emerge among low-status children. The results are discussed in the context of intergroup contact literature, with emphasis on the implications of imagined contact for educational settings.     

Sequencing Rules for Productivity Improvements in Underground Coal Mining*

In this paper, we report on a unique two-machine, dynamic sequencing problem that was involved in a project designed to improve the productivity of underground coal mining operations. It was discovered that mine output was dependent on the particular sequence of faces the continuous miner and bolter worked. The problem is characterized by two unique features. First, the problem is unique because of the geological and safety constraints that must be satisfied by the sequence. Second, the scheduling problem is dynamic because the available job sets change as work progresses, and the production times change as coal is mined. Three heuristic approaches were developed and tested using mine parameters. The best heuristic had a worst case scenario of being within 2.7 percent of the optimal sequence and only a 1.1 percent chance of determining a better sequence. This heuristic resulted in an 8.1 percent productivity improvement.