互联网、技能偏向与农村流动人口就业

在互联网普及和应用不断提升的背景下,互联网对于农村流动人口就业的影响需要受到高度重视.从技能偏向的视角,在文献梳理的基础上,基于理论假设,建立理论模型和实证模型,基于国家卫生和计划生育委员会流动人口动态监测数据,从农村流动人口的就业数量和就业质量角度,分析了互联网的发展对于流动人口就业的影响.研究发现:互联网所导致的技能偏向,能够显著降低对流动人口就业时间的需求,不利于流动人口就业,但能够显著提升流动人口的就业稳定性,有助于提升流动人口的就业质量.基于研究结论,从提升流动人口信息素养、促进就业与社会融合的双赢以及提升流动人口劳动技能多元化角度,提出了相应的政策建议.     

Double-sampling regression-cum-exponential estimator of the mean of a sensitive variable

ABSTRACT

A flexible scrambled response model using a randomization device for quantitative sensitive data is used to evaluate the protection of respondents’ privacy. A double-sampling regression-cum-exponential estimator is used to estimate the mean of a sensitive variable using the mean of a nonsensitive auxiliary variable under scrambled response. The expected bias, the expected mean square error, and the minimum mean square error of this exponential-type estimator are expressed. Simulations and empirical results show that the proposed estimator under scrambled response model has a lower mean square error and a lower bias than the ratio and the exponential estimators.     

Transmission Probabilities and Reproduction Numbers for Sexually Transmitted Infections with Variable Infectivity: Application to the Spread of HIV Between Low- and High-Activity Populations

Probabilities of transmission and numbers of secondary cases are given for an infection which is transmitted sexually by individuals engaged in multiple partnerships with specified durations and timings. The results applied to the human immunodeficiency virus (HIV) hinge on a function which captures the dependence of the per coital act probability of transmission on the time since disease onset and on the duration of infection at death. Reproduction numbers are derived in a heterogeneous population consisting of low- and high-activity men and women. An expression for the basic reproduction number R ₀ of this system sheds light on the role of concurrency, on the timing of the partnerships, and on bridging effects. A high-activity group can cause a significant epidemic outbreak no matter how small the bridging effect, as long as it is not 0. Only if the bridging effect is eliminated altogether can the growth factor in the low-activity group be reduced independently of what happens in the high-activity group. The role of the relationship between client and sex worker and the role of bridging populations in sub-Saharan Africa are assessed.