Bayesian estimation of the Hurst parameter of fractional Brownian motion

The primary purpose of this study was to find Bayesian estimates for the Hurst dimension of a Fractional Brownian motion with a Beta prior when the process is observed at discrete times. Overestimation is observed though the overestimation is less severe as real H goes up. In addition, the estimated H decreases as Beta parameters go up given an Alpha value. In contrast, the estimated H increases as Alpha parameters go up given a Beta value. For the real-world data, the 2011 daily Taiwan stock index was used and the estimated Hurst index was 0.21.     

A bayesian signal detection procedure for scale‐space random fields

The authors consider the problem of searching for activation in brain images obtained from functional magnetic resonance imaging and the corresponding functional signal detection problem. They develop a Bayesian procedure to detect signals existing within noisy images when the image is modeled as a scale space random field. Their procedure is based on the Radon‐Nikodym derivative, which is used as the Bayes factor for assessing the point null hypothesis of no signal. They apply their method to data from the Montreal Neurological Institute.     

Impact of demographic variables on women’s economic empowerment: An ordered probit model

The present study aimed to empirically examine the demographic variables that determine women’s economic empowerment. A sample of 500 married women between 21 and 49 years old (M_age = 35.49, SD = 7.66) was conveniently selected from district Multan (Pakistan). Control over economic resources was used as a proxy for women’s economic empowerment. Ordered probit regression was run to assess the demographic determinants (i.e., age, education, paid job, income, and property) of economic empowerment of the least empowered, moderately empowered, and highly empowered women. Paid job, age, income, and property appeared as positive and significant predictors of women’s economic empowerment. Implications of the study were also discussed.     

Quantitative models for optimal rest period scheduling

Mathematical and simulation models studying work-rest schedules in a production process are developed to arrive at an optimal rest policy to maximize work output per unit time. A CSMP simulation study is used to test the sensitivity of the results for different specific cases.     

Relationship Between Sarcopenia and Fracture Risks in Obese Postmenopausal Women

ABSTRACT

It is known that obesity is inversely correlated with fracture risk. It remains unclear if a low muscle mass (sarcopenia) modulates the relationship between obesity and bone mass density. Twenty-seven obese women were matched for total fat mass (± 0.5 kg) and age (± 4 yrs) and divided in 3 equal groups: class II sarcopenic, class I sarcopenic, and nonsarcopenic. Body composition (DXA) and dietary intake were measured. Our results suggest that obesity may offer some protection against osteoporosis, even in sarcopenic postmenopausal women. However, further studies are needed to examine the actual implication of these results on a clinical standpoint.     

Changes in racial identification and the educational attainment of American Indians, 1970–1990

We use data from the 1970, 1980, and 1990 census public-use files to assess the impact of newly identified Indians on the educational attainment of American Indians who were at least 25 years old in 1970. We test the hypotheses that this impact was limited to metropolitan areas and to states with small Indian populations. We find that educational attainment for American Indians rose sharply between 1970 and 1990 and that changes in racial identification were an important component of this increase in 1980 but not in 1990. Increases in educational attainment were concentrated in metropolitan areas and occurred in states with large and small Indian populations.     

Practical beliefs vs. scientific beliefs: two kinds of maximization

There are two kinds of beliefs. If the ultimate objective is wellbeing (utility), the generated beliefs are “practical.” If the ultimate objective is truth, the generated beliefs are “scientific.” This article defends the practical/scientific belief distinction. The proposed distinction has been ignored by standard rational choice theory—as well as by its two major critics, viz., the Tversky/Kahneman program and the Simon/Gigerenzer program. One ramification of the proposed distinction is clear: agents who make errors with regard to scientific beliefs (e.g., the conjunction fallacy) should not be taken as committing irrationality—because they are most probably engaging the other kind of maximization, the pursuit of wellbeing.     

The adoption of deferred share unit plans for outside directors: economic and social determinants

This paper investigates the antecedents of adopting deferred compensation plans for corporate directors. Relying on agency and network theories, we compare the economic and social characteristics of firms that have adopted a deferred share unit plan for their directors over the 1997–2005 period (130 firms) to a control sample. Our findings show that firms where outside directors have higher agency costs, firms having a block holder that owns a significant voting power, firms whose outside directors serve on other boards having adopted deferred compensation plans, and firms that hire compensation consultants are more likely to adopt a deferred share unit plan for their directors than other firms. These findings highlight the importance of integrating economic and social perspectives when investigating the diffusion of compensation practices.     

Measuring the learning organization culture,organizational commitment and job satisfaction in the Lebanese banking sector

The growing interest developed around the learning organization concept and its impact on work-related outcomes in the West has not been matched yet in other parts of the world. The purpose of this quantitative study was to identify the relationships among the learning organization culture, employee job satisfaction and organizational commitment in the Lebanese banking sector. Results showed positive and significant correlations among the different variables but no interaction effect of the Lebanese social patterns.     

URBAN TRANSPORT AND CRIME: EVIDENCE FROM UNANTICIPATED MASS TRANSIT STRIKES

We examine the effects of mass transit strikes on criminal behavior in Los Angeles County utilizing a unique dataset of reported crimes between 2000 and 2007. Geocoded location and time information pertaining to each offense accommodates a fine grained difference‐in‐differences panel data analysis. We find that in locations affected by the strike, aggravated assaults rose by 18.7% while aggregate property crimes increased by 5.7%, relative to their mean. This increase in crime was disproportionately larger in lower income neighborhoods, which report higher usage of mass transit, suggesting local isolation of both criminals and victims as a mechanism. (JEL J52, K42, K31)