基于策略、成本的移动机制对合作的影响

面对一般意义的社会合作困境,基于合作的演化理论成为经济学、生物学和社会学中重要的研究内容。本文在二维方格上的囚徒困境博弈中引入一个基于策略与成本的移动机制,通过计算机仿真模拟了行为群体的动态演化过程。结果表明：基于策略与成本的移动机制在较广的参数空间内提高了合作水平;同时,模型逻辑也揭示其主要原因在于两个方面,其一,基于策略的移动机制有效地促进了网络中合作者团块的涌现,为合作者的出现提供了有利的条件;另一方面,基于成本的移动有效地调节了主体移动的速率。合作者团块的出现增加了合作者的收益进而减少了背叛者寻找合作者的速率,为稳定的合作秩序的演化提供了有利的保证。     

农村剩余劳动力转移理论的比较研究

“三农”问题是中国建设和谐社会的关键，但解决“三农”问题的一个前提是农村剩余劳动力的成功转移。在新世纪的前20年，在惠及千百万广大人民的小康社会的建设过程中，研究和解决这一问题有着重大的意义。需要对农村剩余劳动力转移的理论进行系统研究，从而为剩余劳动力转移的实践，提供有力的指导。     

户籍对价、劳动力迁移与土地流转

土地流转的根本目的在于社会经济发展方式的转变,需要城市化的大力发展,劳动力迁移和土地流转是城市化发展的一个重要环节。然而,在中国目前的制度约束下,户籍制度成为劳动力迁移的退出和进入壁垒。户籍制度之所以成为城市化的一个障碍,就在于附着于其上的福利价值,所以,要消除这一障碍必须交换其福利价值。本文认为,在农村劳动力城市化迁移中,通过户籍对价来解决迁移劳动力的土地退出和城市安置,不仅能够鼓励劳动力迁移,而且也有利于土地流转。这是一种可行的户籍改革措施和城市化的发展策略。     

中国农村劳动力迁移影响因素研究——基于Probit模型的实证分析

农村劳动力迁移对于缩小城乡收入差距、促进中国经济增长具有非常重要的作用。本文通过中国健康与营养调查(CHNS)数据库的成人调查问卷2004和2006年的数据,采用probit模型定量分析了中国农村劳动力迁移的影响因素。本文的研究发现:婚姻状况、健康、娱乐偏好等变量对农村劳动力的迁移决策有比较显著的影响,而当前收入的影响并不明显。此外,家庭负担并不是迁移决策的影响因素,并且已婚女性劳动力倾向于和丈夫共同迁移,以上两个因素共同导致了农村的空巢老人问题。最后,促进农村劳动力迁移的最有效方法是提高农村劳动力的受教育水平,其中大学及大专学校教育最有效,其次是职业和技术学校教育。     

改性聚苯醚吸收法测定高分子食品接触材料高温下全迁移物析出量

建立了改性聚苯醚吸收法测定食品接触材料高温下全迁移物析出量的方法,并对取样方法、提取溶剂、吸附物净化、加热温度、提取周期以及系统稳定性进行讨论。本方法RSD为2.3%-2.6%（n=10）,具有操作简单、快速等特点。能够满足对食品接触材料高温下全迁移物析出量的分析要求。     

The impact of migration on food consumption patterns: The case of Vietnam

This paper explores the relationship between migration and consumption patterns using panel data from the 2004 and 2006 Vietnam Household Living Standards Surveys. Employing an instrumental variable approach to control for the endogeneity of migration, our results indicate that short-term migration has a positive effect on overall per capita food expenditures, per capita calorie consumption and food diversity. Long-term migration also appears to be positively related to consumption, but impacts are often insignificant and of a lesser magnitude than short-term migration. The results provide no evidence of negative effects of migration, and support the view that short-term migration is a mechanism by which households maintain food security. The results suggest that to improve food security the Vietnamese government should enact policies that facilitate short-term migration flows as well as the transferring of remittances.     

Migration and child development during the food price crisis in El Salvador

Migration is often used as parts of both ex post and ex ante strategies to mitigate risks to household incomes. There is little empirical evidence, however, of the way that migration actually helps households in times of shocks. In this paper, I describe how the peak of the worldwide food price crisis affected anthropometric statistics among young children in El Salvador, and how households with access to international migrants were not affected as negatively as households without such access. In 2008, El Salvador experienced food price inflation of 15%, and the evaluation of Red Solidaria, El Salvador’s conditional cash transfer program, shows that height-for-age (HAZ) Z scores among children under 3 years old declined by 0.2 standard deviations on average. In this paper, I use the Red Solidaria evaluation data to assess whether children in households with access to remittances or international migrants were better off than households without access to migration income. Using both repeated cross-sectional data and individual panel data, I find that as theory would expect, children in households with access to international migrants have much lower declines in their HAZ scores.     

Labour market response to globalisation: Spain, 1880–1913

This paper analyses the impact of globalisation (trade and migration) on the Spanish labour market between 1880 and 1913 by examining the influence that globalisation factors had on agricultural and industrial wages. Our results show that the nineteenth century grain invasion had a negative impact on agricultural wages, whereas the fall in wheat prices did not benefit industry workers. We also found that migration pushed up real agricultural and industrial wages. As agriculture was the main sector in the economy, the final impact was a wage decrease. The negative impact of trade on agricultural and industrial labour markets partly explains the trade policy response of “integral protection”. However, other alternatives that would have been effective in raising living standards, such as migration policy, were not used.     

Customers’ migration paths decided by relative advantage: longitudinal and comparative case study of successive generations of logic semiconductor technology

ABSTRACT

Understanding customers and their behaviour has become important for success in a market. When successive generations of technology are available in a market, customers will decide their migration paths based on certain factors. This study focused on the relative advantage of successive generations positioned at different levels. Based on a longitudinal and comparative research design, the migration paths of customers are identified by understanding how their behaviours are affected by this relative advantage. The preferred relative advantage is positioned differently at early and majority markets. According to observations of the actual migration paths of 14 semiconductor customers, early and majority market players exhibit different migration paths (switching, new entrance, leapfrogging, or diffusion paths) depending on the relative advantage of the migrating generation. This study has theoretical implications by understanding the mechanism of customers’ migration based on the relative advantage, as well as practical implications for suppliers and customers to sustain their competitive advantage in a market.     

Migration to the agricultural frontier and wealth accumulation, 1860-1870

I use a new data set of households linked between the 1860 and 1870 censuses to study frontier migration. Households that moved to the frontier to farm were more likely than non-migrants to have been poor, landless, and illiterate, and to have had young children. Also, after controlling for observable differences, migrants had below average abilities to accumulate wealth. These findings suggest fewer opportunities for migrants to accumulate wealth in non-frontier areas and a reason for their migration. Nonetheless, migrants fared well, accumulating wealth at high rates. The gains in wealth of migrants, especially those with long tenure on the frontier, suggest the extraordinary benefits of migration.