Adaptive testing in arch models

Specification tests for conditional heteroskedasticity that are derived under the assumption that the density of the innovation is Gaussian may not be powerful in light of the recent empirical results that the density is not Gaussian. We obtain specification tests for conditional heteroskedasticity under the assumption that the innovation density is a member of a general family of densities. Our test statistics maximize asymptotic local power and weighted average power criteria for the general family of densities. We establish both first-order and second-order theory for our procedures. Simulations indicate that asymptotic power gains are achievable in finite samples.     

Net migration and migration effectiveness: A comparison between Australia and the United Kingdom, 1976–96 Part 1: Total migration patterns

A nation’s population is redistributed through migration flows and counterflows between its constituent subnational areas, resulting in a geographical pattern of net migration gains or losses which may change from one time period to another. Migration effectiveness is the indicator commonly used to measure net migration as a proportion of gross migration turnover for any territorial unit. This paper explores the effect of net migration in two different countries, Australia and the United Kingdom, using measures of migration effectiveness computed from period-age migration data sets for a system of city regions assembled for four consecutive five-year periods in each country. While the evidence suggests that the overall effectiveness of net migration has declined over the 20-year period in both countries, marked similarities and contrasts are apparent in the spatial patterning of migration that together provide useful analytical insights into the changing space economies of the two countries.     

Transition into Retirement Affects Life Satisfaction: Short- and Long-Term Development Depends on Last Labor Market Status and Education

The effect of retirement on life satisfaction is a research topic that received a lot of attention, yet provided heterogeneous results. The current study suggests a remedy for this situation by taking two predictors of diversity (i.e. education and last labor market status) into account. We assumed that changes in social status and changes in resources influence retirement adjustment. The social status change affects retirees in the short-term, whereas individuals’ resources indicated by education predict long-term adjustment. To disentangle these processes, we contrasted exits from full-time employment and transitions from unemployment. We used data from the German Socio-Economic Panel to estimate a multi-group, multi-episodes dual change score model. The development of life satisfaction is lastingly interrupted by retirement. A short-term increase in life satisfaction was found for both transition groups but was more pronounced for those being previously unemployed. Life satisfaction develops in the long-term education-specific: retirees who have more education show almost constant life satisfaction whereas those retirees who have less education experience a decline. The results indicate that retirement entails a major change in the way people live. Adjustment to this can be characterized by two processes: A status change enfolds in the short-term. A building of new daily routines using individuals’ resources develops in the long-term. Both processes can be interpreted in terms of cumulative inequality: last labor market status differences decrease in the short-term but remain. Educational differences increase after retirement.     

B股向境内居民开放对市场信息不对称的影响——买卖价差分解方法

投资者之间的信息不对称严重影响了市场的有效性.运用买卖价差分解技术,把价差分解成流动性价差和信息不对称价差,比较了它们在B股开放前后的差异,研究了B股向境内居民开放这一事件对市场信息不对称的影响.结论表明,境内居民参与交易虽然增加了股票流动性,但并没有改善市场交易者之间的信息不对称环境.     

A non-linear mixed-effects model to predict cumulative bole volume of standing trees

For purposes of forest inventory and eventual management of the forest resource, it is essential to be able to predict the cumulative bole volume to any stipulated point on the standing tree bole, while requiring measurements of tree size that can be made easily, quickly and accurately. Equations for this purpose are typically non-linear and are fitted to data garnered from a sample of felled trees. Because the cumulative bole volume of each tree is measured to numerous upper-bole locations, correlations between measurements within a tree are likely. A mixed-effects model is fitted to account for this within-subject (tree) correlation structure, while also portraying the sigmoidal shape of the cumulative bole volume profile.