美国深空网的同波束干涉测量技术

讨论了美国NASA深空网(DSN)对深空飞船所采用的同波束干涉(SBI)技术概念和测量原理，并介绍了这一技术的应用和发展情况。     

Unit roots and infrequent large shocks: new international evidence on output

The nature and magnitude of the economic shocks that have affected the per capita GDP of 16 OECD countries are analyzed over a long period using the outlier method. Strong proof of infrequent large permanent and transitory shocks were found, essentially resulting from the two major wars in the twentieth century, the recession in the 1920s, the Great Depression, among others. We also examine the nature of the output trend by combining different tests of non-stationarity on different GDP series corrected by the outliers detected. It is shown that the per capita GDP series cannot reject the unit root hypothesis in 13 of the 16 countries examined. No conclusion could be drawn for the other countries because the test results were contradictory.     

Separating microstructure noise from volatility

There are two variance components embedded in the returns constructed using high frequency asset prices: the time-varying variance of the unobservable efficient returns that would prevail in a frictionless economy and the variance of the equally unobservable microstructure noise. Using sample moments of high frequency return data recorded at different frequencies, we provide a simple and robust technique to identify both variance components.     

Further Evidence on PPP Adjustment Speeds: the Case of Effective Real Exchange Rates and the EMS*

Two different approaches intend to resolve the ‘puzzling’ slow convergence to purchasing power parity (PPP) reported in the literature [see Rogoff (1996) , Journal of Economic Literature, Vol. 34.] On the one hand, there are models that consider a non‐linear adjustment of real exchange rate to PPP induced by transaction costs. Such costs imply the presence of a certain transaction band where adjustment is too costly to be undertaken. On the other hand, there are models that relax the ‘classical’ PPP assumption of constant equilibrium real exchange rates. A prominent theory put together by Balassa (1964, Journal of Political Economy, Vol. 72) and Samuelson (1964 Review of Economics and Statistics, Vol. 46) , the BS effect, suggests that a non‐constant real exchange rate equilibrium is induced by different productivity growth rates between countries. This paper reconciles those two approaches by considering an exponential smooth transition‐in‐deviation non‐linear adjustment mechanism towards non‐constant equilibrium real exchange rates within the EMS (European Monetary System) and effective rates. The equilibrium is proxied, in a theoretically appealing manner, using deterministic trends and the relative price of non‐tradables to proxy for BS effects. The empirical results provide further support for the hypothesis that real exchange rates are well described by symmetric, nonlinear processes. Furthermore, the half‐life of shocks in such models is found to be dramatically shorter than that obtained in linear models.     

Time Series Concepts for Conditional Distributions*

The paper asks the question – as time series analysis moves from consideration of conditional mean values and variances to unconditional distributions, do some of the familiar concepts devised for the first two moments continue to be helpful in the more general area? Most seem to generalize fairly easy, such as the concepts of breaks, seasonality, trends and regime switching. Forecasting is more difficult, as forecasts become distributions, as do forecast errors. Persistence can be defined and also common factors by using the idea of a copula. Aggregation is more difficult but causality and controllability can be defined. The study of the time series of quantiles becomes more relevant.     

Non‐linear Predictability of UK Stock Market Returns*

Linear predictability of stock market returns has been widely reported. However, recently developed theoretical research has suggested that due to the interaction of noise and arbitrage traders, stock returns are inherently non‐linear, whereby market dynamics differ between small and large returns. This paper examines whether an exponential smooth transition threshold model, which is capable of capturing this non‐linear behaviour, can provide a better characterization of UK stock market returns than either a linear model or an alternate non‐linear model. The results of both in‐sample and out‐of‐sample specification tests support the exponential smooth transition threshold model and hence the belief that investor behaviour does differ between large and small returns.     

Regulation And The Rise In Asset-Based Mutual Fund Management Fees

In this article I explain why asset‐based fees are common for mutual fund management companies and why the average fee has increased recently. I argue that Securities and Exchange Commission fee regulations make alternative fee types illegal or unattractive. Management companies can maintain higher fees because regulations and brand‐name capital partly insulate them from competition and because investors cannot easily distinguish between performance‐oriented and marketing‐oriented fund companies. Index funds and unit investment trusts may offer competition to mutual funds in the future because they are designed to minimize management fees.     

Nonlinear Drift And Stochastic Volatility: An Empirical Investigation Of Short-Term Interest Rate Models

In this article I provide new evidence on the role of nonlinear drift and stochastic volatility in interest rate modeling. I compare various model specifications for the short‐term interest rate using the data from five countries. I find that modeling the stochastic volatility in the short rate is far more important than specifying the shape of the drift function. The empirical support for nonlinear drift is weak with or without the stochastic volatility factor. Although a linear drift stochastic volatility model fits the international data well, I find that the level effect differs across countries.     

反倾销规则与“中欧石材案”

反倾销规则是 WTO允许的世界各国均可采用的维护公平贸易秩序、抵制不正当竞争的重要手段之一 ,其规则非常严密 ,主要是明确规定了反倾销必须同时具备的三个条件及反倾销的程序。WTO成立以后 ,各成员方纷纷修改本国的反倾销法律 ,我国于 2 0 0 1年 12月 10日颁布了《中华人民共和国反倾销条例》,使之与 WTO的反倾销规则相一致。同时 ,也在积极利用 WTO反倾销规则来反对他国反倾销的滥用。 2 0 0 1年引起各界广泛关注的欧盟对我国石材业反倾销申诉案 ,经涉诉的我国 2 7家企业的积极应诉 ,终以欧盟撤诉 ,我方取得全面胜利而告终。这是我国按照 WTO原则建立自我保护体系 ,有效保护本国经济利益和经济发展的重要举措。意味着我国政府也将利用反倾销这把“利剑”来保护国内企业     

Productivity growth in Indian agriculture: is there evidence of convergence across states?

This paper explores the question of convergence in total factor productivity (TFP) in agriculture across fourteen major agricultural states of India. Using a Törnqvist–Theil index for TFP growth for the period 1973–1993, we find no evidence to support convergence to a single TFP level (σ‐convergence). After grouping the various states on the basis of their productivity performance, we find that the high‐performing states show a gradual movement towards the trend, whereas the low‐performing states generally show more volatility. Testing for long‐run convergence in levels of agricultural productivity, we find evidence of conditional beta‐convergence after controlling for state‐specific factors and idiosyncratic year‐specific volatility. The results are robust to alternative specifications of tests of unit root in panel data developed recently.