The Roy model has more precise predictions about the self-selection of migrants than previously realized. The conditions shown to result in positive or negative selection in terms of expected earnings also imply a stochastic dominance relationship between the earnings distributions of migrants and non-migrants. We test these predictions using the Danish full population administrative data. We f...

Using a field experiment in China, we study whether migration status is correlated with attitudes toward risk, ambiguity, and competitiveness. Our subjects include migrants and non-migrants. We find that, migrants exhibit no differences from non-migrants in risk and ambiguity preferences elicited using pairs of lotteries; however, migrants are significantly more likely to enter competition in t...

This paper looks at the connection between internal migration and unemployment in South Africa. We examine whether rural-urban migrants are more likely to be unemployed, in informal sector employment or underemployed than non-migrants. We build on standard economic theory to predict that rates of unemployment and of participation in the informal sector ought to be much higher for migrants than ...

BACKGROUND The increase in urban migrants is one of major challenges for tuberculosis control in China. The different characteristics of tuberculosis cases between urban migrants and local residents in China have not been investigated before. METHODOLOGY/PRINCIPAL FINDINGS We performed a retrospective study of all pulmonary tuberculosis patients reported in Songjiang district, Shanghai, to de...

Migrants from rural Mexico usually move abroad with the idea to return once they have improved their economic situation. Although they do not always go back, Mexican migrants often plan their return before leaving. In any case, the imagined return persists for a long time in their minds. This paper analyzes the ways in which rural migrants from southern Veracruz and western Mexico imagine a bet...

1st instar larvae of myrmecaeurus trigrammus (pallas, 1771) collected in behesht mustapha marivan reared in laboratory condition , larvae fed with ants.the molting time, onset of diapause, carefully recorded .characteristics of 3rd instar larva, and the morphological details of larva, and imago ,described and figures drawn.

BACKGROUND In many European countries including Germany, migrants utilize preventive services less frequently than the majority population. This is also true for the utilization of dental checkups. Little is known about which demographic, social, behavioral, and health-related factors influence the decision of migrants to seek preventive dental health care and how these factors differ from thos...

Two snail species belonging to genus Lymnaea, L.auricularia and L.gedrosiana, were collected from 6 different districts of Shadegan area of Khoozestan. Eight percent of the total collections of the snails revealed the occurrence of larva in them. The prevalence of larva within the snails varied in different districts may be due to different geoclimatic conditions and availability of fresh water...

Whole body sterol metabolism in insects has seldom been studied. We were able to design an appropriate study at a butterfly farm in Belize. We collected six larvas of butterfly (Morpho peleides), their food (leaves of Pterocarpus bayessii), and their excretions. In addition, six adult butterflies were collected. The sterols of the diet, the larva, and adult butterfly were analyzed by gas-liquid...