Inflation Expectations and Risk Premiums in an Arbitrage‐Free Model of Nominal and Real Bond Yields

Differences between yields on comparable‐maturity U.S. Treasury nominal and real debt, the so‐called breakeven inflation (BEI) rates, are widely used indicators of inflation expectations. However, better measures of inflation expectations could be obtained by subtracting inflation risk premiums (IRP) from the BEI rates. We provide such decompositions using an affine arbitrage‐free model of the term structure that captures the pricing of both nominal and real Treasury securities. Our empirical results suggest that long‐term inflation expectations have been well anchored over the past few years, and IRP, although volatile, have been close to zero on average.     

建构主义学习设计在数学建模课程教学中的运用

数学建模课程的开设架设起学生已有知识和实际问题的解决之间的一道桥梁,强调培养学生主动发现问题、分析问题、与人合作共同探索的能力。这一思想与建构主义学习理论是相通的。在具体教学方法上采用建构主义学习设计构建良好的课堂学习环境,可以更好的达到数学建模课程的教学目标。     

基于鼠标的FDM快速成形实验研究

利用实验室熔融沉积快速成形机FDM200mc,以鼠标的三维设计为蓝本,系统展示了鼠标从电脑屏幕到实体模型的全部过程,完整体现CAD/CAM技术。同时在实验基础上对工艺参数设置(分层厚度、支撑方式、支撑角度)等进行详细解析。     

A Benchmark Approach to Filtering in Finance

The paper proposes the use of the growth optimal portfolio for pricing and hedging in incomplete markets when there are unobserved factors that have to be filtered. The proposed filtering framework is applicable also in cases when there does not exist an equivalent risk neutral martingale measure. The reduction of the variance of derivative prices for increasing degrees of available information is measured. 1991 Mathematics Subject Classification: primary 90A09; secondary 60G99; 62P20 JEL Classification: G10, G13     

Regime-switching and interest rates in the European monetary system

This paper examines the impact that a currency target zone has on short-term interest rates. For a number of countries in the European Monetary System, we characterize the short rate using a regime-switching model that allows for a differently parameterized mean-reverting square-root process in each regime. We find that the volatility, the level, and the speed-of-adjustment are all higher in the regime that is operative during speculative attacks and currency crises. Moreover, we allow the conditional probability of being in each regime to be state-dependent so the model can be used to examine questions relating to the likelihood of realignments and the stability of the target zone system.     

Integrating expected coverage and local reliability for emergency medical services location problems

Daskin's MEXCLP model [Daskin M. A maximum expected covering location model: formulation, properties, and heuristic solution. Transportation Science 1983;17:48-70] was one of the first efforts to capture the stochastic nature of emergency medical services (EMS) location problems within a mixed-integer formulation. With their subsequent introduction of MALP, ReVelle and Hogan [The maximum availability location problem. Transportation Science 1989;23:192-200] offered two key advances, local vehicle busyness estimates and the α-reliability objective. While these constructs have influenced many subsequent EMS location models, they have been subjected to relatively little empirical analysis. To address this, we introduce the LR-MEXCLP, a hybrid model combining the local busyness estimates of MALP with the maximum coverage objective of MEXCLP. We then solve a series of problems with all three models and employ simulation to estimate aggregate service levels. We find that LR-MEXCLP leads to modest but consistent service gains over both MALP and MEXCLP. These results support the merits of local busyness estimates, but they also suggest that the α-reliability objective may be inappropriate when seeking to maximize aggregate system response capabilities. More generally, our research underscores the utility of (a) linking modeling assumptions and goals with real-world application contexts, and (b) employing simulation or other techniques to validate theoretical results.     

论数学建模思想在高等数学教学中的渗透

高等数学是工科学生的必修课，数学建模是提高学生综合素质，锻炼分析问题能力和动手能力的一种高级形式。在高等数学教学中融入数学建模思想是搞好高等数学教学，充分发挥数学重要作用的有效手段和途径。     

The impact of the Internet on human activity–travel patterns: analysis of gender differences using multi-group structural equation models

The widespread use of the Internet for conducting various types of activities may be leading to considerable change in people’s activity–travel patterns. Past studies, however, have left many issues unaddressed. Using an Internet-activity diary dataset and multi-group structural equation modeling, this study examines the complex interactions between different types of Internet and physical activities, with a special focus on gender differences and Internet maintenance and leisure activities. The results indicate that the impacts of Internet activities on people’s activity–travel patterns are significantly different across gender. In general, Internet use for maintenance purposes has a greater impact on women’s activity–travel in the physical world, while Internet use for leisure purposes affects men’s physical activities and travel to a greater extent. Further, breaking Internet activities down into different categories reveals some hidden patterns that would not have been detected if these different types of Internet activities were lumped together as a single category.     

Sustainable development. With or without mankind?

The author challenges the conventional wisdom that the main risk to Western development is environmental degradation caused by mankind. Concern over the greenhouse effect and global warming have more to do with millenium fever than reality. There is still very little evidence to suggest that these environmental phenomena result from human activity. What we do know is that there have been major cyclical fluctuations throughout history. The author cautions against implementing ‘scientistic’ policies in the face of such doubts, just because it is trendy to do so.     

A forecasting comparison of some var techniques

Higher dimensional multivariate time series models suffer from the problem of over-parametrisation which impairs their forecasting performance. Starting from such unrestricted vector autoregressive models the paper discusses two ways to cope with this difficulty. The first approach reduces the number of free parameters by applying a subset modelling strategy. The second approach takes a Bayesian point of view by formulating ‘priors’ which are then combined with sample information, but leaving the original specification unaltered. Using Austrian quarterly macroeconomic time series a comparative study is undertaken by running alternative forecasting exercises. Both methods improve out-of-sample forecasting performance substantially at the cost of some bias in ex-post simulations. Comparing the ex-ante predictions of the two approaches, the former does better at short horizons whereas the latter gains as the forecast horizon lengthens.