Cross‐sectional Restrictions on the Spot and Forward Term Structures of Interest Rates and Panel Unit Root Tests

In this paper we examine the stationarity of all the rates comprising the USD, GBP, DM and JPY spot and forward term structures. Instead of focussing on short maturity interest rates, as most other papers do, we perform a detailed analysis of the whole range of spot and forward interest rates of the 4 main currencies. We investigate the issue of stationarity within the framework of an equilibrium interest rate model such as Vasicek (1977), that defines the cross-sectional and time series properties that interest rates of various maturities must satisfy. We show that within a one-factor interest rate model, such as Vasicek, all interest rates are restricted to exhibit the same mean reverting behaviour. This restriction allows us to apply more powerful panel unit root tests. This methodology increases considerably the number of observations available and as a result the power of the unit root tests. The higher power of these tests allows us to demonstrate that there does exist mean reversion on the spot and forward US interest rates and the forward DM and GBP interest rates.     

Bivariate mixed normal GARCH models and out-of-sample hedge performances

This study compares bivariate mixed normal GARCH models with standard bivariate GARCH models in terms of the percentage variance reduction of the out-of-sample hedged portfolio and also statistical significance tests of performance improvements using Superior Predictive Ability statistics. All competing models are applied to corn and wheat futures and empirical results demonstrate that the standard BEKK-GARCH model significantly outperforms the other competing GARCH models at shorter horizons. However, as the hedge horizon is extended to longer than 10 days, it is evident that the mixed normal BEKK-GARCH model is the best at the usual significance level of 5%.     

Commodity Prices and Unit Root Tests

Price theory suggests that commodity prices should be stationary series. Yet, tests for unit roots rather frequently imply that these prices are not stationary. This seeming inconsistency is investigated by applying alternative specifications of unit root tests to prices of corn, soybeans, barrows and gilts, and milk. The preponderance of evidence suggests that nominal prices do not have unit roots, but the results are sensitive to the specification of the test equation. Accounting for a structural change that shifts the mean appears to be an important issue in unit root tests.     

浅议地质调查项目实验测试工作预算方法--存在的问题及建议

按现行的预算编制要求,地质调查实验测试费用需拆分至相关财务费用科目并作为执行和审计的依据,但经估算,拆分数据与实际发生费用相去甚远。实验测试经费预算中存在的问题：(1)预算编制中无法“精细预算”、预算标准与实际情况不吻合;(2)实验测试工作周期不确定、受野外工作情况制约,实验测试类委托业务无法严格按照预算执行。对改进实验测试预算编制方法的建议：(1)实验测试预算管理跳出“费用科目”拆分,在预算中以工作手段体现,建议在预算附表中增加“实验测试费”表;(2)实验测试预算不区分是否为委托业务;(3)对实验测试工作手段标准进行动态调整;(4)给出实验测试工作适当的预算调整空间。     

Tests for the Role of Risk Aversion on Input Use

For risk-averting agents, risks alter production decisions while the existence of institutions to insure against adverse states of nature will likely restore decisions toward levels under risk neutrality. In this article, conditions are identified on a stochastic technology to test   H^rn _0,≤  : that risk averters choose smaller input levels than risk neutral agents, and   H^ra _0,≤  : that an increase in risk aversion reduces input use. A robust statistical method to test for dominance is adapted to stochastic production relations. It is found that   H^rn _0,≤  is likely true for nitrogen application on Iowa corn. Weaker evidence is found in favor of   H^ra _0,≤  .     

On Jumps and ARCH Effects in Natural Resource Prices: An Application to Pacific Northwest Stumpage Prices

Continuous-time models of natural resource prices usually preclude the possibility of large changes (jumps) resulting from unexpected events. To test for the presence of jumps and/or ARCH effects, we combine bounds and the Monte Carlo test technique to obtain finite-sample, level-exact p -values. We apply this methodology to stumpage prices from the Pacific Northwest and find evidence of jumps and ARCH effects. To assess the impact of neglecting jumps on the decision to harvest old-growth timber, we develop an autonomous, infinite-horizon stopping model for which we provide a new method of resolution. Our numerical results show the importance of modeling jumps explicitly.     

API Spec 5L(44版)关于材料及试验的变化

针对API Spec 5L(44版)标准,简要分析了API 5L(44版)标准对于材料与理化试验方面与前一版本的变化。新版API 5L标准相比以前版本更加精简,实际使用更方便,在理化试验方面细节上变化较大,在焊管的实际生产应用中应予以注意。     

Random walk and efficiency tests in the Asia-Pacific foreign exchange markets: Evidence from the post-Asian currency crisis data

This paper empirically tests the random walk and efficiency hypothesis for 12 Asia-Pacific foreign exchange markets. The hypothesis is tested using individual as well as panel unit root tests and two variance-ratio tests. The study covers the high (daily) and medium (weekly) frequency post-Asian crisis spot exchange rate data from January 1998 to July 2007. The inferential outcomes do not differ substantially between the unit root tests and the variance-ratio tests when using daily data but differ significantly when using weekly data. With the daily data, both types of unit root tests identify unit root components for all the series and two variance-ratio tests provide the evidence of martingale behavior for majority of the exchange rates tested. With the weekly data, panel unit root tests identify unit root component for the exchange rates and, the unit root tests on a single series basis identify unit root component for 10 foreign exchange markets. However, the variance-ratio tests reject the martingale null for the majority of the exchange rates when using weekly data.     

Locally Most Powerful and Other Rank Tests for Independence – with a Contaminated Weighted Alternative

Several authors in the literature have attempted the quantification of the concept of stochastic dependence for bivariate distribution. Two weighted rank tests for testing independence against a weighted contamination alternative is proposed and their distributional properties are studied. We also derived a locally most powerful rank test for the alternative setting. The rank tests proposed are shown to be asymptotic locally most powerful for specific distributions.     

Testing Multiple Non-Nested Factor Demand Systems

This article explains how to obtain straightforward extensions of the most popular univariate non‐nested statistics, and of the RESET‐test, to a multivariate context and examines how to use these tests to compare alternative factor demand systems. The empirical application involves the classical Berndt–Khaled KLEM data set. A statistically adequate specification is determined for each competing factor demand system. The empirical results are interpreted for each system, the models are compared on the basis of multivariate paired and joint non‐nested procedures and practical indications about what to expect if these tests are applied to alternative factor demand specifications are provided.