土工实验中的液、塑限测定浅议

文章分析了当前土工实验中的液、塑限测定过程中应当注意的问题及其存在的问题,并论述了如何对其实验数据进行处理和分析的方法。     

基于BP网络对我国通货膨胀率的预测及其分析

本文首先由我国的CPI计算出通货膨胀率,综合分析了我国通货膨胀率和GDP增长率数据。其次,用带有动量项和自适应学习率的BP神经网络预测出2008～2009年我国CPI,从而推算出2008～2009年我国通货膨胀率分别是4.99%和4.91%左右。并提出了一些相应的政策建议。     

International interest rates and US monetary policy announcements: Evidence from Hong Kong and Singapore

This paper investigates the responses of market interest rates to US monetary policy announcements for the US and two emerging economies, Hong Kong and Singapore which are similar on many respects but have experienced opposite exchange rate regimes in the last twenty years. Our results, based on market expectations extracted from federal fund futures rates, document that FOMC announcements significantly affect the term structure of interest rate in the US and both Asian countries. Further, international interest rate differentials around FOMC meeting dates tend to be negative for short maturities with the impact gradually dissipating as bond maturity increases. Finally, for the case of Singapore, we find that domestic interest rates react to both external and domestic monetary policy announcements with a magnitude that is larger over the full bond maturity spectrum for domestic announcements. These results are robust to time-varying futures risk premia and alternative measures of interest rates expectations.     

Generalized piecewise linear histograms

We extend the concept of piecewise linear histogram introduced recently by Beirlant, Berlinet and Györfi. The disadvantage of that histogram is that in many models it takes on negative values with probability close to 1. We show that for a wide set of models, the extended class of estimates contains a bona fide density with probability tending to 1 as the sample size n increases to infinity. The mean integrated absolute error in the extended class of estimators decreases with the same rate n^–2/5 as in the original narrower class.     

Inflation,interest and exchange rates in the transition1

Central and Eastern European economies have made extraordinary progress in their trade and exchange regimes. Surprisingly, instant convertibility was established for a great variety of exchange rate regimes. In spite of diversity, all these countries have followed a common pattern: severe initial undervaluation - the cost of speed and unrestricted trade - followed by rapid real revaluation and incipient protectionism. Since 1994 in many cases an embarrass de richesse has appeared: high capital inflows which are either inflationary or costly to sterilize. A major cause of these flows - or at any rate of the high cost of sterilization - is the presence of significant interest rate differentials higher than required to cover the risk of devaluation. These are the necessary consequence of a policy of positive real interest rates and of real revaluation from excessively undervalued exchange rates. Lower interest rates are recommended, both to stem financial capital inflows and to reduce the cost of their sterilization.     

Do high interest rates defend currencies during speculative attacks?

Do high interest rates defend currencies during speculative attacks? Or do they have the perverse effect of increasing the probability of a devaluation of the currency under attack? Drawing on evidence from a large sample of speculative attacks in developed and developing economies, this paper argues that the answer to both questions is ‘no’. In particular, this paper documents a striking lack of any systematic association whatsoever between interest rates and the outcome of speculative attacks. The lack of clear empirical evidence on the effects of high interest rates during speculative attacks mirrors the theoretical ambiguities on this issue.     

Real exchange rate targeting and macroeconomic instability

Using an optimizing model of a small open economy, this paper studies the macroeconomic effects of PPP rules whereby the government increases the devaluation rate when the real exchange rate—defined as the price of tradables in terms of nontradables—is below its long-run level and reduces the devaluation rate when the real exchange rate is above its long-run level. The paper shows that the mere existence of such a rule can generate aggregate instability due to self-fulfilling expectations. The result is shown to obtain in both flexible- and sluggish-price environments.     

Sources of Bank Interest Rate Risk

We investigate bank stocks'sensitivity to changes in interest rates and the factors affecting this sensitivity. We focus on whether the exposure of commercial banks to interest rate risk is conditioned on certain balance sheet and income statement ratios. We find a significantly negative relation between bank stock returns and changes in interest rates over the period 1991–1996. We also find that bank characteristics measured from basic financial statement information explain bank stocks'sensitivity to interest rate changes. These results suggest that bank managers, analysts, and regulators can use this information to assess the relative risk exposure of banks.     

Price Rigidity and the Selection of the Exchange Rate Regime

We evaluate and qualify Friedman's, 1953, “case for flexible exchange rates” in the presence of sticky prices in a two country model. We find that a flexible regime performs indeed better when the degree of nominal price rigidity is high while a bilateral peg does better when prices are fairly flexible. This result obtains independent of whether monetary policy is activistic or not and is mostly due to the negative relationship between employment and productivity shocks when prices are relatively sluggish (Gali, 1999). A unilateral peg tends to produce the lowest level of world welfare but it sometimes represents the best monetary arrangement for the pegger. JEL Classification Numbers: E32, E52, F33, F42     

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.