On the Deng-Lin random number generators and related methods

We study the structure and point out weaknesses of recently proposed random number generators based on special types of linear recurrences with small coefficients, which allow fast implementations. Our theoretical analysis is complemented by the results of simple empirical statistical tests that the generators fail decisively. Directions for improvement and alternative generators are also pointed out.     

Besoins individuels et collectifs: Nanacatlan,Mexico

The author intends both to describe a native credit institution in a peasant community and to analyse its overt and covert functions. The community fund, managed by the local authority (presidencia auxiliar) is theoretically available to all household heads who can show solvency (e.g., by pawning a piece of property, usually land). Apart from assisting peasants who face a shortage of cash, another overt function of the system is to finance, with the interests which are paid back on the loans, the functioning of the local administration. Because of the great economic discrepancies between peasants (50 per cent of them own no land, while 2.5 per cent own 30 per cent of the land) one real, although covert, function of the credit institution is to channel a substantial amount of cash to the local upper class (which has little access to banking facilities). Therefore it actually enhances their economic domination over the majority of villagers, which fact allows us to understand the strict control they have exerted over the management of the fund since its foundation, some 40 years ago.     

Epidemiologic network inference

Statistics and Computing - In many epidemiologic models, a disease is assumed to spread along a contact network. We aim to infer this network, in addition to the epidemiologic model parameters,...     

Child welfare workers' practice in cases involving domestic violence

This paper reports the findings of an exploratory and qualitative study of child welfare workers' practice in cases involving domestic violence. The research aimed to focus on child welfare workers' interventions with families experiencing domestic violence, elements influencing the child welfare workers' decisions, and the factors facilitating and creating obstacles for intervention. An analysis of the qualitative data showed that child welfare workers have different ways of intervening in cases involving domestic violence. Also, the interventions were especially centred on women victims of violence and they were held responsible for protecting their children. Finally, the dilemmas and difficulties which child welfare workers face in these cases are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Mental Imagery and Production of Hand Gestures While Speaking in Younger and Older Adults

Speech and conversational hand gestures were recorded during interviews of 23 younger (M = 21 years) and 19 older adults (M = 70 years). Three kinds of questions were used in order to activate either visual images, motor images, or no mental image (abstract topics). On average, the rate of gesture production did not differ in younger and older adults, but it was significantly influenced by imagery conditions. Gesture production was higher in the motor than in the visual imagery condition, and lowest in the abstract condition. A significant interaction between age and imagery conditions influenced the proportion of representational gestures, which were relatively less frequent in older adults, especially in the visual imagery condition. Content analysis of verbal responses showed that imagery values did not differ in younger and older adults, but that concrete words were less frequent in responses to abstract questions than in the two other conditions. The implications of these results concerning the mechanisms of gesture production and the age-related changes in conversational behavior are discussed.     

Wage Bargaining with On‐the‐Job Search: Theory and Evidence

Most applications of Nash bargaining over wages ignore between‐employer competition for labor services and attribute all of the workers' rent to their bargaining power. In this paper, we write and estimate an equilibrium model with strategic wage bargaining and on‐the‐job search and use it to take another look at the determinants of wages in France. There are three essential determinants of wages in our model: productivity, competition between employers resulting from on‐the‐job search, and the workers' bargaining power. We find that between‐firm competition matters a lot in the determination of wages, because it is quantitatively more important than wage bargaining à la Nash in raising wages above the workers' “reservation wages,” defined as out‐of‐work income. In particular, we detect no significant bargaining power for intermediate‐ and low‐skilled workers, and a modestly positive bargaining power for high‐skilled workers.