Tests of the martingale hypothesis for foreign currency futures with time-varying volatility

The martingale hypothesis for daily and weekly rates of change of futures prices for five currencies is tested in this paper. With daily data, we find some evidence against the null hypothesis for each currency. Although institutionally imposed limits on daily price changes were binding fairly often in the earlier years of the sample, the results are not substantially different when data affected by limit moves are removed. Trading day effects in foreign currency futures and spot prices introduce complicated day of the week patterns in futures price. For this reason, we retest the martingale hypothesis with weekly data and reject the null hypothesis for only one currency. For this currency, one interpretation of the evidence is that a time-varying risk premium exists.     

Consumption-based CAPM with belief heterogeneity

This paper finds that the risk–return relationship of the consumption-based CAPM is robust to the heterogeneity in agents׳ beliefs. First, the effect of disagreement cancels out in the limit as risk tolerance approaches zero. Second, although low risk aversion and large disagreement can significantly distort the security market line (SML) and the effect is amplified in a dynamic model, per capita volatility of consumption growth is implausibly high compared to empirical estimates from microeconomic data. Third, increasing risk aversion and lowering disagreement levels can help to reduce per capita volatility, however the impact of disagreement on the SML also become negligible.     

An intertemporal CAPM with higher-order moments

We propose an intertemporal asset pricing model that incorporates both preference for higher-order moments and stochastic investment opportunities and encompasses a wide range of existing models. We provide supporting evidence from the U.S. stock market and find that, not only is systematic skewness negatively priced, an extra return premium is also required for accepting high systematic risk associated with a rise in risk aversion. Our findings suggest that considering both skewness preference and intertemporal hedging demands improves the estimated risk-return trade-off, and that cross-sectional anomalies such as value, momentum, and failure probability puzzles can be partially explained by our model.     

Separating a mixture of two normals with proportional covariances

We propose a simple affine equivariant clustering method, based on the idea of best linear classification, for samples from a mixture of two multivariate normal distributions with different mean vectors but proportional covariance matrices. To ameliorate the curse of dimensionality, a non-parametric approach to find candidates for a best linear discriminant function is presented. By using simulation studies and a real example, we show that for large samples in high dimensions, the proposed method can be a useful supplement to general-purpose multivariate outlier detection methods.     

A dynamic CAPM with supply effect: Theory and empirical results

Breeden [Breeden, D. T. (1979). An intertemporal asset pricing model with stochastic consumption and investment opportunities. Journal of Financial Economics 7, 265–196] and Grinols [Grinols, E. L. (1984). Production and risk leveling in the intertemporal capital asset pricing model. The Journal of Finance 39, 5, 1571–1595] and Cox et al. [Cox, J. C., Ingersoll, J. E., Jr., & Ross, S. A. (1985). An intertemporal general equilibrium model of asset prices. Econometrica 53, 363–384] have described the importance of supply side for the capital asset pricing. Black [Black, S. W. (1976). Rational response to shocks in a dynamic model of capital asset pricing. American Economic Review 66, 767–779] derives a dynamic, multiperiod CAPM, integrating endogenous demand and supply. However, Black's theoretically elegant model has never been empirically tested for its implications in dynamic asset pricing. We first theoretically extend Black's CAPM. Then we use price, dividend per share and earnings per share to test the existence of supply effect with U.S. equity data. We find the supply effect is important in U.S. domestic stock markets. This finding holds as we break the companies listed in the S&P 500 into ten portfolios by different level of payout ratio. It also holds consistently if we use individual stock data.     

资产定价模型(CAPM)在住房抵押贷款证券化(MBS)定价中的应用

20世纪80年代以来,住房抵押贷款证券化(MBS)在我国有了长足的发展,为了对住房抵押贷款证券化产品进行合理定价,本文引入CAPM模型来确定正确反应证券风险的贴现率,并且分析了CAPM模型的产生以及发展过程,最后对其进行动态的修正.     

具有结构突变的CAPM的阶段异方差和自相关性的调整LM检验

由于金融市场是动荡不定的,资产定价模型CAPM往往会出现结构突变,异方差,序列相关,因此需要对CAPM的随机误差进行齐性检验。对于具有单个结构突变点的CAPM,本文得到了检验阶段异方差和自相关性的调整LM检验统计量。Monte Carlo模拟的结果显示,该调整LM检验统计量具有比普通LM检验统计量更好的检验功效。最后,我们用一个具体的实例论证了方法的有效性。     

Adaptive estimation of autoregressive models with time-varying variances

Stable autoregressive models are considered with martingale differences errors scaled by an unknown nonparametric time-varying function generating heterogeneity. An important special case involves structural change in the error variance, but in most practical cases the pattern of variance change over time is unknown and may involve shifts at unknown discrete points in time, continuous evolution or combinations of the two. This paper develops kernel-based estimators of the residual variances and associated adaptive least squares (ALS) estimators of the autoregressive coefficients. Simulations show that efficiency gains are achieved by the adaptive procedure.     

基于CAPM的国际投资分析

随着经济全球化发展,国际投资日益多元化,因此,如何选择国际投资方式成为众多投资者的关注目标。文章以崭新的视角,采用评价证券组合的资本资产理论来对跨国并购进行分析论证,对跨国并购的溢出效应进行量化分析,帮助决策者进行判断。     

A note on the existence of CAPM equilibria with homogeneous cumulative prospect theory preferences

This note identifies and fixes a minor gap in Proposition 1 in Barberis and Huang (Am Econ Rev 98(5):2066–2100, 2008). Assuming homogeneous cumulative prospect theory decision makers, we show that CAPM is a necessary (though not sufficient) condition that must hold in equilibrium. We support our results with numerical examples where security prices become negative.     

基于CAPM的黄金风险溢价研究

运用CAPM理论中的边际风险价格的概念,通过分析一个包含了黄金市场和股票市场在内的市场资产组合,定量给出了黄金的风险溢价。同时检验了黄金收益是否在CAPM框架内有效。在与我国股市进行比较之后,得出投资者可将黄金包括到投资组合中去,以取得更好的风险收益比。     

Stochastic frontier models with multiple time-varying individual effects

This paper proposes a flexible time-varying stochastic frontier model. Similarly to Lee and Schmidt [1993, In: Fried H, Lovell CAK, Schmidt S (eds) The measurement of productive efficiency: techniques and applications. Oxford University Press, Oxford], we assume that individual firms’ technical inefficiencies vary over time. However, the model, which we call the “multiple time-varying individual effects” model, is more general in that it allows multiple factors determining firm-specific time-varying technical inefficiencies. This allows the temporal pattern of inefficiency to vary over firms. The number of such factors can be consistently estimated. The model is applied to data on Indonesian rice farms, and the changes in the efficiency rankings of farms over time demonstrate the model’s flexibility.

Forecasting economic time series with unconditional time-varying variance

The classical forecasting theory of stationary time series exploits the second-order structure (variance, autocovariance, and spectral density) of an observed process in order to construct some prediction intervals. However, some economic time series show a time-varying unconditional second-order structure. This article focuses on a simple and meaningful model allowing this nonstationary behaviour. We show that this model satisfactorily explains the nonstationary behaviour of several economic data sets, among which are the U.S. stock returns and exchange rates. The question of how to forecast these processes is addressed and evaluated on the data sets.     

Cointegrating rank selection in models with time-varying variance

Reduced rank regression (RRR) models with time varying heterogeneity are considered. Standard information criteria for selecting cointegrating rank are shown to be weakly consistent in semiparametric RRR models in which the errors have general nonparametric short memory components and shifting volatility provided the penalty coefficient _Cn→∞$C_n\to \infty$ and _Cn/n→0$C_n/n\to 0$ as n→∞$n\to \infty$. The AIC criterion is inconsistent and its limit distribution is given. The results extend those in Cheng and Phillips (2009a) and are useful in empirical work where structural breaks or time evolution in the error variances is present. An empirical application to exchange rate data is provided.     

Panel data models with multiple time-varying individual effects

This paper considers a panel data model with time-varying individual effects. The data are assumed to contain a large number of cross-sectional units repeatedly observed over a fixed number of time periods. The model has a feature of the fixed-effects model in that the effects are assumed to be correlated with the regressors. The unobservable individual effects are assumed to have a factor structure. For consistent estimation of the model, it is important to estimate the true number of individual effects. We propose a generalized methods of moments procedure by which both the number of individual effects and the regression coefficients can be consistently estimated. Some important identification issues are also discussed. Our simulation results indicate that the proposed methods produce reliable estimates.     

基于CAPM的黄金风险溢价研究

运用CAPM理论中的边际风险价格的概念,通过分析一个包含了黄金市场和股票市场在内的市场资产组合,定量给出了黄金的风险溢价.同时检验了黄金收益是否在CAPM框架内有效.在与我国股市进行比较之后,得出投资者可将黄金包括到投资组合中去,以取得更好的风险收益比.     

CAPM模型对上证钢铁板块的实证研究

根据CAPM模型的原理,本文就上海股票市场钢铁板块的全部20只股票的系统性风险以及股权分置改革对其系统性风险的影响进行了实证分析。发现了许多我国股市发展中的存在的许多问题,说明近年来中国股市虽有较快发展,但仍然是一个不成熟的股市。     

Two remarks on the uniqueness of equilibria in the CAPM

In the standard ‘capital asset pricing model’ (CAPM) with a riskless asset we give a sufficient condition for uniqueness. This condition is a joint restriction on the agents’ endowments and their preferences which is compatible with non-increasing absolute risk aversion and which is in particular satisfied with constant absolute risk aversion. Moreover, in the CAPM without a riskless asset we give an example for multiple equilibria even though all agents have constant absolute risk aversion.     

Tests of cointegrating rank with a trend-break

The conventional testing procedure may mislead one into accepting the null of no cointegration or the null of a cointegrating rank smaller than the true rank when there is a trend-break under the alternative hypothesis. This paper proposes tests for cointegrating rank that have power against the trend-break alternative. The proposed tests are applied to the US money demand function. The results support the Campbell–Perron conjecture: money, income and interest rates are cointegrated around a broken trend.     

The maturity structure of term premia with time-varying expected returns

This paper analyzes the maturity structure of term premia using McCulloch’s US Treasury yield curve data from 1953–91, allowing expected returns to vary across time. One, 3, 6, and 12 month holding period returns on maturities up to 5 years are projected on 3 ex ante variables to compute time-varying expected returns, and simulations are employed to generate distributions of conditionally expected return premia. The likelihood of expected returns monotonically increasing in maturity (as implied by the liquidity preference hypothesis) is relatively high when the yield curve is steep and interest rates are high, and with longer holding periods, but low in other cases. The hypothesis that intermediate maturity bonds have the highest expected returns (a “hump-shaped” maturity-return pattern) around the onset of recessions does not receive much support.