The Sustainability of Indian Fiscal Policy: A Reassessment of the Empirical Evidence

This paper reassesses the sustainability of fiscal policy in India from 1950 to 2010. Overall, the evidence broadly supports the hypothesis that the fiscal policy is "weakly" sustainable and documents a higher speed of adjustment to the intertemporal budget constraint than earlier papers do. Notwithstanding this improvement in the fiscal outlook, the author suggests that India should pursue a policy of fiscal consolidation in the years ahead, both because the ratio of public debt to the gross domestic product is still high compared to other emerging market countries and because "weak" fiscal solvency implies potential adverse consequences on the management of public debt.     

Using Market Expectations to Test for Speculative Bubbles in the Crude Oil Market

The wide fluctuations of oil prices from 2003 to 2008 have attracted the interest of academics and policymakers. A popular view is that these fluctuations were caused by speculative bubbles due to the increased financialization of oil futures markets. This hypothesis, however, is difficult to examine since the fundamental price of oil is unobservable and, therefore, econometric evidence in favor of bubbles may actually be due to misspecified market fundamentals. In this paper, we extend two recently proposed methodologies for bubble detection that alleviate this problem by using market expectations of future prices. Both methodologies provide no evidence of speculative bubbles.     

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。     

Modeling Mexican agricultural production

Results of time series tests (including unit root and deterministic and stochastic cointegration tests) imply that a mixture of differenced and cointegrated model specifications are warranted for econometric models of Mexican agricultural supplies and input demands. Test results are sensitive to choice of functional form and the set of regressors. For example, share equations should be estimated using differenced data, but output supply and input demand equations generally should not. Generalized Leontief and quadratic functional forms are preferred over the translog. Symmetry and curvature of a restricted profit function are rejected. Short-run output supplies and input demands are generally inelastic. First version received: February 1998/Final version received: November 1998     

Nonlinear IV unit root tests in panels with cross-sectional dependency

We propose a unit root test for panels with cross-sectional dependency. We allow general dependency structure among the innovations that generate data for each of the cross-sectional units. Each unit may have different sample size, and therefore unbalanced panels are also permitted in our framework. Yet, the test is asymptotically normal, and does not require any tabulation of the critical values. Our test is based on nonlinear IV estimation of the usual augmented Dickey–Fuller type regression for each cross-sectional unit, using as instruments nonlinear transformations of the lagged levels. The actual test statistic is simply defined as a standardized sum of individual IV t-ratios. We show in the paper that such a standardized sum of individual IV t-ratios has limit normal distribution as long as the panels have large individual time series observations and are asymptotically balanced in a very weak sense. We may have the number of cross-sectional units arbitrarily small or large. In particular, the usual sequential asymptotics, upon which most of the available asymptotic theories for panel unit root models heavily rely, are not required. Finite sample performance of our test is examined via a set of simulations, and compared with those of other commonly used panel unit root tests. Our test generally performs better than the existing tests in terms of both finite sample sizes and powers. We apply our nonlinear IV method to test for the purchasing power parity hypothesis in panels.     

压力测试及其在金融机构风险管理中的运用

本文研究和评价了目前被国际大型金融机构积极采用的风险管理工具:压力测试。作者通过将压力测试与VaR作比较等方法详细阐述了压力测试的特征、使用方法和缺陷,并且进一步分析指出压力测试在金融机构风险管理中的作用及其最新发展状况和趋势,最后着重分析了压力测试在我国运用和发展的前景并提出建议。     

Testing the CAPM revisited

This paper re-examines the tests of the Sharpe–Lintner Capital Asset Pricing Model (CAPM). The null that the CAPM intercepts are zero is tested for ten size-based stock portfolios and for twenty five book-to-market sorted portfolios using five-year, ten-year and longer sub-periods during 1965–2004. The paper shows that the evidence for rejecting the CAPM on statistical grounds is weaker than the consensus view suggests, and highlights the pitfalls of testing multiple hypotheses with the conventional heteroskedasticity and autocorrelation robust (HAR) test with asymptotic P-values. The conventional test rejects the null for almost all sub-periods, which is consistent with the evidence in the literature. By contrast, the null is not rejected for most of the sub-periods by the new HAR tests developed by Kiefer et al. (2000), Kiefer and Vogelsang (2005), and Sun et al. (2008).     

The robustness of modified unit root tests in the presence of GARCH

We consider the valuation of energy storage facilities within the framework of stochastic control. Our two main examples are natural gas dome storage and hydroelectric pumped storage. Focusing on the timing flexibility aspect of the problem we construct an optimal switching model with inventory. Thus, the manager has a constrained compound American option on the inter-temporal spread of the commodity prices. Extending the methodology from Carmona and Ludkovski [Appl. Math. Finance, 2008], we then construct a robust numerical scheme based on Monte Carlo regressions. Our simulation method can handle a generic Markovian price model and easily incorporates many operational features and constraints. To overcome the main challenge of the path-dependent storage levels, two numerical approaches are proposed. The resulting scheme is compared with the traditional quasi-variational framework and illustrated with several concrete examples. We also consider related problems of interest, such as supply guarantees and mines management.     

A note on spurious nonlinear regression

This paper explores the power of two tests for nonlinearity against spurious nonlinear regression. Results show that while the BDS test is susceptible to spuriousness, an approach introduced by Peña and Rodriguez [Peña, D. and Rodriguez, J., 2005, Detecting nonlinearity in time series by model selection criteria, International Journal of Forecasting 21, 731–748.] is powerful, regardless of sample size.     

Trading frequency and event study test specification

We examine the effects of thin trading on the specification of event study tests. Simulations of upper and lower tail tests are reported with and without variance increases on the event date across levels of trading volume. The traditional standardized test is misspecified for thinly traded samples. If return variance is unlikely to increase, then Corrado's rank test provides the best specification and power. With variance increases, the rank test is misspecified. The Boehmer et al. standardized cross-sectional test (Event-study methodology under conditions of event-induced variance, Journal of Financial Economics 30, pp. 253–272) is properly specified, but not powerful, for upper-tailed tests. Lower-tailed alternative hypotheses can best be evaluated using the generalized sign test.