Likelihood-based specification analysis of continuous-time models of the short-term interest rate

An extensive collection of continuous-time models of the short-term interest rate is evaluated over data sets that have appeared previously in the literature. The analysis, which uses the simulated maximum likelihood procedure proposed by Durham and Gallant (2002), provides new insights regarding several previously unresolved questions. For single factor models, I find that the volatility, not the drift, is the critical component in model specification. Allowing for additional flexibility beyond a constant term in the drift provides negligible benefit. While constant drift would appear to imply that the short rate is nonstationary, in fact, stationarity is volatility-induced. The simple constant elasticity of volatility model fits weekly observations of the three-month Treasury bill rate remarkably well but is easily rejected when compared with more flexible volatility specifications over daily data. The methodology of Durham and Gallant can also be used to estimate stochastic volatility models. While adding the latent volatility component provides a large improvement in the likelihood for the physical process, it does little to improve bond-pricing performance.     

现代服务业：上海经济增长的新动力

本文通过经济增长弹性与就业弹性两个指标,对上海"十一五"规划中提出将优先发展的现代服务业及其主要子行业在上海经济增长中的作用进行了研究。分析认为目前上海第二产业与第三产业对经济的拉动力相当。而现代服务业的拉动力大于传统服务业。近年来,现代服务业的就业弹性均值较大,同时弹性的波动变化很大,这是上海GDP就业弹性近几年波动增大的主要原因。同时,通过对现代服务业中主要子行业的分析,发现现代服务业子行业间就业弹性的变动有着高度的正相关,这将增加现代服务业就业弹性波动对于上海GDP就业弹性波动的影响。     

发达国家科技政策导向及其启示

当今世界,科技政策已成为许多国家尤其是美、日、欧等发达国家全力打造科技强国的基本的公共政策。文章从国家战略引导产业发展、国家政策促进产业发展、全力追求知识与技术创新、注重培养和吸纳优秀人才等4个方面对此进行了探析。     

Do homeowners achieve more household wealth in the long run?

Despite the public’s faith in homeownership as a vehicle for wealth creation, there are surprisingly few empirical studies of the independent impact of homeownership and its duration on household wealth accumulation. This paper provides the first empirical evidence that homeownership, after controlling for other drivers of wealth accumulation, is positively and significantly associated with wealth accumulation over time. Using the Panel Survey of Income Dynamics, it examines the influence of housing tenure choices between 1989 and 2001 on household net wealth levels in 2001 after controlling for initial wealth in 1989, location, income, education, and other family and personal characteristics that might influence the rate of wealth accumulation. Importantly, the models used also control for the tendency of households to accumulate wealth between 1984 and 1989 (five years prior to the studied period). This approach is used to address the possibility that an unobserved variable—the propensity to save or accumulate wealth—may be associated with both the probability and duration of homeownership and the rate of wealth accumulation. All else equal, those who owned homes and owned for longer periods of time had significantly higher household net wealth by 2001. These results are compelling because house price appreciation over the period was near its long-run average while stock gains were above and real rent increases below their long-run averages. Hence, the findings are suggestive of a positive influence of ownership over long periods on net wealth, even during a period when alternative investments produced higher than normal returns and rents grew slowly. This is especially important because the overwhelmingly majority of households do not sell their homes shortly after buying them. In our sample, those who became owners typically owned for 7 years. Furthermore, most households that bought during a period of declining real home values in the early 1990s continued to own their homes for at least eight years and came out well ahead of those who did not own.     

Sequential Malmquist Indices of Productivity Growth: An Application to OECD Industrial Activities

The paper applies both the standard DEA methodology with contemporaneous frontiers and DEA with sequential frontiers to study changes in productivity and efficiency in manufacturing for a sample of eleven OECD countries over a twenty-year period. It uses a decomposition of the industrial Malmquist productivity indices to locate the sources of productivity growth: 'technical progress' and 'catching up.' The alternative indices are interrelated in a unifying framework that provides an interpretation to their difference. We argue that for manufacturing industries, in which technological regress is unlikely to occur, DEA with sequential frontiers provides a more adequate measure for the contribution of technical changes than standard DEA.     

增长机会与资本结构——对我国生物制药行业上市公司的实证研究

本文从公司战略及外部资本市场环境出发,对我国生物制药行业上市公司的增长机会与资本结构的相关性进行了实证研究,结果发现该行业上市公司增长机会与其债务水平呈显著负相关。     

Forecasting economic time series using flexible versus fixed specification and linear versus nonlinear econometric models

Nine macroeconomic variables are forecast in a real-time scenario using a variety of flexible specification, fixed specification, linear, and nonlinear econometric models. All models are allowed to evolve through time, and our analysis focuses on model selection and performance. In the context of real-time forecasts, flexible specification models (including linear autoregressive models with exogenous variables and nonlinear artificial neural networks) appear to offer a useful and viable alternative to less flexible fixed specification linear models for a subset of the economic variables which we examine, particularly at forecast horizons greater than 1-step ahead. We speculate that one reason for this result is that the economy is evolving (rather slowly) over time. This feature cannot easily be captured by fixed specification linear models, however, and manifests itself in the form of evolving coefficient estimates. We also provide additional evidence supporting the claim that models which ‘win’ based on one model selection criterion (say a squared error measure) do not necessarily win when an alternative selection criterion is used (say a confusion rate measure), thus highlighting the importance of the particular cost function which is used by forecasters and ‘end-users’ to evaluate their models. A wide variety of different model selection criteria and statistical tests are used to illustrate our findings.     

Sources of Sectoral Growth in an Economy Wide Context: The Case of U.S. Agriculture

Growth in U.S. agriculture is linked to the non-farm economy through domestic terms of trade and factor market adjustments. With almost stable input growth, the relatively large contributions from growth in Total Factor Productivity (TFP) are passed on to intermediate and final consumers in the form of declining real prices for primary farm products. The resulting net growth in the real value of farm output (GDP) is relatively low (0.25% per annum). The decomposition of TFP suggests that public agricultural stock of knowledge and infrastructure are robustly associated with TFP growth, while spill-overs from private agricultural and economy wide research and development (R and D) are positive but, relatively small.     

物流中的新设施—自动化立体仓库

当今物流速度日益加快，仓库建设和改造向空间、立体化、自动化快速发展，建设自动化立体仓库是今后的必然趋势。结合多年实践．对物流领域成件货物储存的新设施，自动化立体仓库进行了详细阐述。     

计件工资博弈中管理者的守诺与公平权衡——对计件工资制不流行的再解释

本文首先回顾总结了计件工资制度的发展过程和存在的问题,指出计件工资博弈陷入低效僵局的原因在于管理者的不履行事先的承诺。传统的解释是管理者事后抵挡不住自利的诱惑,本文认为管理者守诺还是不守诺是在权衡计件工资员工和计时工资员工激励效果后作出的理性的选择。管理者守诺只在一定的情形下发生所以计件工资制不流行。