中国股债市场长期动态相关性的影响因素研究——基于宏观不确定性和协动性视角

本文借鉴现代宏观经济学中的无套利仿射模型,基于"定价核"的定价方式,将股票市场和债券市场收益率之间的相关系数分解为其主要驱动因素--通货膨胀、真实利率和股息率的不确定性,以及三者之间的协方差。在实证部分,采用DCC-MGARCH模型计算股票市场和债券市场收益率的动态相关系数,验证中国股债相关性的时变规则;进而通过回归分析探究所选取的解释变量对中国股债相关性的贡献。结果表明,通货膨胀和股息率的不确定性以及真实利率与通货膨胀和股息率各自之间的协动性是影响这种相关性的主要因素;通胀冲击、真实利率和股息率可以解释这种相关性与长期动态的暂时背离。其中,通货膨胀和股息率的不确定性对股债相关性的影响与其他欧美主要经济体有着不同的表现,反映了中国市场的特殊性;此外,相较于中国经济市场的平稳时期,股市动荡期间各经济因素的影响会发生改变,且模型解释力会降低。     

Stock and bond joint pricing,consumption surplus,and inflation news

In this paper, Bekaert et al.’s (2010) model is modified by allowing consumption growth to depend on dividend yield rather than dividend growth. With a simplified inflation dynamic, the general equilibrium model is characterized by a system of linear and affine stochastic equations. From these equations, a closed-form solution jointly pricing equity and bonds is derived. The generalized method of moments is used to demonstrate that our model’s calibrated moments broadly match the first and second moments of stocks, bonds, and other macroeconomic variables in the US. Our estimated equity premium is 6.0%, which closely matches its actual value of 5.6%. The predicted risk aversion is countercyclical. Moreover, an out-of-sample test indicates the significant improvement of predictive power on the price–dividend ratio over Campbell and Cochrane’s (1999) model. Our model can further capture the dramatic increase in the price–dividend ratio after the 1990s.     

The Gilt-Equity Yield Ratio and the Predictability of UK and US Equity Returns

A number of financial variables have been shown to be effective in explaining the time-series of aggregate equity returns in both the UK and the US. These include, inter alia , the equity dividend yield, the spread between the yields on long and short government bonds, and the lagged equity return. Recently, however, the ratio between the long government bond yield and the equity dividend yield – the gilt-equity yield ratio – has emerged as a variable that has considerable explanatory power for UK equity returns. This paper compares the predictive ability of the gilt-equity yield ratio with these other variables for UK and US equity returns, providing evidence on both in-sample and out-of-sample performance. For UK monthly returns, it is shown that while the dividend yield has substantial in-sample explanatory power, this is not matched by out-of sample forecast accuracy. The gilt-equity yield ratio, in contrast, performs well both in-sample and out-of-sample. Although the predictability of US monthly equity returns is much lower than for the UK, a similar result emerges, with the gilt-equity yield ratio dominating the other variables in terms of both in-sample explanatory power and out-of-sample forecast performance. The gilt-equity yield ratio is also shown to have substantial predictive ability for long horizon returns.     

The Gilt-Equity Yield Ratio and the Predictability of UK and US Equity Returns

A number of financial variables have been shown to be effective in explaining the time-series of aggregate equity returns in both the UK and the US. These include, inter alia , the equity dividend yield, the spread between the yields on long and short government bonds, and the lagged equity return. Recently, however, the ratio between the long government bond yield and the equity dividend yield – the gilt-equity yield ratio – has emerged as a variable that has considerable explanatory power for UK equity returns. This paper compares the predictive ability of the gilt-equity yield ratio with these other variables for UK and US equity returns, providing evidence on both in-sample and out-of-sample performance. For UK monthly returns, it is shown that while the dividend yield has substantial in-sample explanatory power, this is not matched by out-of sample forecast accuracy. The gilt-equity yield ratio, in contrast, performs well both in-sample and out-of-sample. Although the predictability of US monthly equity returns is much lower than for the UK, a similar result emerges, with the gilt-equity yield ratio dominating the other variables in terms of both in-sample explanatory power and out-of-sample forecast performance. The gilt-equity yield ratio is also shown to have substantial predictive ability for long horizon returns.     

Inflation illusion and the dividend yield: evidence from the UK

We report evidence that the UK dividend yield and expected inflation are positively correlated from 1962 to 1997, but negatively correlated subsequently. Using a commonly used VAR (vector auto-regression)-based procedure we find strong evidence that the positive correlation is caused both by inflation illusion and the effect of inflation on required rates of return. We also find some evidence that it is caused by inflation rationally reducing expected real dividend growth. We find that Chen and Zhao's (2009. “Return Decomposition.” Review of Financial Studies 22 (12): 5213–5249) criticism of the VAR-based procedure has little empirical relevance but that the procedure can be highly sensitive to the choice of data period.     

The high-frequency impact of news on long-term yields and forward rates: Is it real?

Macroeconomic news announcements move yields and forward rates on nominal and index-linked bonds and inflation compensation. This paper estimates the reactions using high-frequency data on nominal and index-linked bond yields, allowing the effects of news announcements on real rates and inflation compensation to be parsed far more precisely than is possible using daily data. Long-term nominal yields and forward rates are very sensitive to macroeconomic news announcements. Inflation compensation is sensitive to announcements about price indices and monetary policy. However, for news announcements about real economic activity, such as nonfarm payrolls, the vast majority of the sensitivity is concentrated in real rates. Accordingly, most of the sizeable impact of news about real economic activity on the nominal term structure of interest rates represents changes in expected future real short-term interest rates and/or real risk premia rather than changes in expected future inflation and/or inflation risk premia. Such sensitivity of real rates to macroeconomics news is hard to rationalize within the framework of existing macroeconomic models.     

Disagreement about inflation and the yield curve

We show that inflation disagreement, not just expected inflation, has an impact on nominal interest rates. In contrast to expected inflation, which mainly affects the wedge between real and nominal yields, inflation disagreement affects nominal yields predominantly through its impact on the real side of the economy. We show theoretically and empirically that inflation disagreement raises real and nominal yields and their volatilities. Inflation disagreement is positively related to consumers’ cross-sectional consumption growth volatility and trading in fixed income securities. Calibrating our model to disagreement, inflation, and yields reproduces the economically significant impact of inflation disagreement on yield curves.     

A consumption-based model of the term structure of interest rates

This paper proposes a consumption-based model that accounts for many features of the nominal term structure of interest rates. The driving force behind the model is a time-varying price of risk generated by external habit. Nominal bonds depend on past consumption growth through habit and on expected inflation. When calibrated to data on consumption, inflation, and the aggregate market, the model produces realistic means and volatilities of bond yields and accounts for the expectations puzzle. The model also captures the high equity premium and excess stock market volatility.     

Equity yields

We study a new data set of dividend futures with maturities up to ten years across three world regions: the US, Europe, and Japan. We use these asset prices to construct equity yields, analogous to bond yields. We decompose the equity yields to obtain a term structure of expected dividend growth rates and a term structure of risk premia, which decomposes the equity risk premium by maturity. We find that the slope of the term structure of risk premia is pro-cyclical, whereas the slope of the term structure of expected dividend growth rates is counter-cyclical. The comovement of yields across regions is, on average, higher for long-maturity yields than for short-maturity yields, whereas the variation in this comovement is much higher for short-maturity yields.     

Real Interest Rates and Inflation: An Ex-Ante Empirical Analysis

We develop a method of measuring ex-ante real interest rates using prices of index and nominal bonds. Employing this method and newly available data, we directly test the Fisher hypothesis that the real rate of interest is independent of inflation expectations. We find a negative correlation between ex-ante real interest rates and expected inflation. This contradicts the Fisher hypothesis but is consistent with the theories of Mundell and Tobin, Darby and Feldstein, and Stulz. We also find that nominal interest rates include an inflation risk premium that is positively related to a proxy for inflation uncertainty.     

The ex ante real rate and inflation premium under a habit consumption model

This paper analyzes and quantifies ex ante components of bond yields – real rate of returns and risk premiums – from observed prices of nominal and indexed bonds in the United Kingdom from 1983 to 2000. The estimation uses an asset pricing framework based on a habit consumption model together with a joint formulation of consumption growth and inflation. Nominal yields carry a time-varying inflation premium that is significant throughout the period, increasing in the bond's maturity and contributing up to 25 basis points to yearly nominal yields. The analysis allows the extraction of the ex ante real rate from indexed bonds by properly taking into account both the incomplete indexation on these instruments and the inflation premium embedded in the nominal bonds.     

Unexpected Inflation,Capital Structure,and Real Risk‐adjusted Firm Performance

Managers can improve real risk‐adjusted firm performance by matching nominal assets with nominal liabilities, thereby reducing the sensitivity of real risk‐adjusted returns to unexpected inflation. The net asset value of US equity real estate investment trusts (REITs) serves as a good proxy for nominal assets and, accordingly, we use a sample of US REITs to test our hypothesis. We find that for the firms in our sample: (i) their real risk‐adjusted performance, and (ii) their inflation‐hedging qualities are inversely related to deviations from this ‘matching‐nominals’ argument. In addition to providing managers with a vehicle to maximize real risk‐adjusted performance, our findings also provide investors with the tools to infer inflation‐hedging qualities of equity investments.     

Risk,uncertainty, and asset prices

We identify the relative importance of changes in the conditional variance of fundamentals (which we call “uncertainty”) and changes in risk aversion in the determination of the term structure, equity prices, and risk premiums. Theoretically, we introduce persistent time-varying uncertainty about the fundamentals in an external habit model. The model matches the dynamics of dividend and consumption growth, including their volatility dynamics and many salient asset market phenomena. While the variation in price–dividend ratios and the equity risk premium is primarily driven by risk aversion, uncertainty plays a large role in the term structure and is the driver of countercyclical volatility of asset returns.     

Extracting inflation expectations and inflation risk premia from the term structure: A joint model of the UK nominal and real yield curves

This paper analyses the UK interest rate term structure over the period since October 1992, when the United Kingdom adopted an explicit inflation target, using an affine term structure model estimated using both government bond yields and survey data. The model imposes no-arbitrage restrictions across nominal and real yields, which enables interest rates to be decomposed into expected real policy rates, expected inflation, real term premia and inflation risk premia. The model is used to shed light on major developments over the period, including the impact of Bank of England independence and the low real bond yield ‘conundrum’.     

The dividend–price ratio does predict dividend growth: International evidence

Unpredictable dividend growth by the dividend–price ratio is considered a ‘stylized fact’ in post war US data. Using long-term annual data from the US and three European countries, we revisit this stylized fact, and we also report results on return predictability. We make two main contributions. First, we document that for the US, results for long-horizon predictability are crucially dependent on whether returns and dividend growth are measured in nominal or real terms, and this difference is due to long-term inflation being strongly negatively predictable by the dividend–price ratio. The impact of inflation is to reinforce real return predictability and to reduce – or change direction of – real dividend growth predictability. This provides an explanation for the strong predictability of long-horizon real returns in the ‘right’ direction, and the strong predictability of long-horizon real dividend growth in the ‘wrong’ direction, that we see in US post war data. Second, we find that predictability patterns in three European stock markets are in many ways different from what characterize the US stock market. In particular, in Sweden and Denmark dividend growth is strongly predictable by the dividend–price ratio in the ‘right’ direction while returns are not predictable. The results for the UK are mixed. Our results are robust to a number of changes in the modeling framework. We discuss the results for dividend growth predictability in terms of the ‘dividend smoothing hypothesis’.     

Inflation Uncertainty, Real-Interest-Rate Uncertainty, and the Liquidity Premium on Government Bonds

This paper shows that the components of uncertainty about nominal interest rates, real-rate uncertainty and inflation uncertainty, have different effects on the liquidity premium. An increase in inflation uncertainty should increase the equilibrium liquidity premium because investors reduce the effect of inflation uncertainty on the riskiness of their portfolios by holding more short-term bonds. In contrast, an investor can reduce the effects of uncertainty about future ex-ante real rates on portfolio return by matching more closely the maturity dates of the bonds held with the date on which the portfolio is to be liquidated for consumption purposes. Thus, the effect of an increase in real-rate uncertainty on the equilibrium liquidity premium is ambiguous, depending on the relative magnitudes of long-term and short-term saving and the proportions of short-term and long-term bonds issued by the government.     

Implicit Inflation and Risk Premiums in the Brazilian Fixed Income Market

The breakeven inflation, the differential between nominal and real yields of bonds, is often used as a predictor of future inflation. The model presented here decomposes this interest rate differential into a risk premium and implicit inflation using a parametric formulation based on no-arbitrage conditions using nominal and indexed yield curves in Brazil, via an affine model of the Nelson–Siegel family. The measures of implicit inflation obtained from the model are shown to be unbiased estimators of future inflation for short horizons and carry some information for long horizons, and the model forecasts are superior to market surveys.     

Dynamic Asset Allocation under Inflation

We develop a simple framework for analyzing a finite-horizon investor's asset allocation problem under inflation when only nominal assets are available. The investor's optimal investment strategy and indirect utility are given in simple closed form. Hedge demands depend on the investor's horizon and risk aversion and on the maturities of the bonds included in the portfolio. When short positions are precluded, the optimal strategy consists of investments in cash, equity, and a single nominal bond with optimally chosen maturity. Both the optimal stock–bond mix and the optimal bond maturity depend on the investor's horizon and risk aversion.     

Capital Gains, Dividend Yields, and Expected Inflation

One explanation for the negative relationship between short-horizon stock returns and inflation is that inflation proxies (inversely) for expected future real output. In this paper, I examine the possibility that inflation also proxies for variation in real price/dividend ratios (excess returns). I show that when the covariance between real price/dividend ratios and inflation is nonzero, the relationship between returns and expected inflation differs for the two components of returns: dividend yields and capital gains returns. My empirical evidence demonstrates that dividend yields and capital gains are related differently to expected inflation in U.S. and foreign markets.     

Estimating the Equity Risk Premium and Expected Equity Rates of Return: The Case of Canada

It is common to use the average excess return of equities over bonds estimated over long time periods as an expected equity risk premium on the grounds that going back far enough covers most possible economic scenarios. But although this data is useful in guiding the exercise of judgment, it cannot substitute for judgment. Adding more years of data to the near century of Canadian stock and bond returns that inform today's estimate of the equity risk premium will not produce a “random walk” for a simple reason: the historic bond series is the result of a specific historic monetary policy. This is particularly true of and important for the case of Canada, where today's very low current bond yields reflect the emergence of the Canadian dollar as a reserve currency as well as the impact of unconventional monetary policy elsewhere. After analyzing the historic record of the Canadian equity risk premium and noting the need for adjustments when this premium is applied to the current anomalously low Canadian long‐term bond yields, the author reaches the following conclusions:

• The historic Canadian equity risk premium is approximately 5.0% (based on arithmetic returns), which is slightly lower than the roughly 6.0% value for the U.S.
• The historic equity risk premium has not been constant because of obvious changes in the Canadian bond market. To some extent, the huge cycle in which bond yields began their increase from the 4.0% level starting in 1957, when markets were liberalized, and then fell back to the 4.0% level in 2007‐2008 completed an adjustment to changes in fiscal versus monetary policy. However, in 2016, average long Canada bond yields dropped to an anomalously low 1.8%, which is below the long‐term inflation target of the Bank of Canada, and have barely recovered since. It is difficult to view this as an equilibrium rate determined by private investors.
• Of the drop in bond yields, about 0.50% is unique to Government of Canada bonds as they became attractive to sovereign investors as a rare AAA‐rated issuer.
• Using an indicator variable for the post‐2010 years, a simple regression analysis indicates that current long Canada bond yields should be about 2.75% higher but for the recent changes. And for 2018, this means that the 2.35% average long Canada bond yield should have been about 5.0%. Apart from the impact of higher government deficits, this is consistent with average yields before the 2008 financial crisis.
• Adding an adjusted 5.0% long Canada bond yield to the historic equity risk premium in Canada of 4.50% gives 9.50% for the cost of the overall equity market or, given the Bank of Canada's target inflation rate of 2.0%, a real equity return of 7.5%, both slightly higher than the long‐run averages.

In sum, the conventional practice of adding a historic market risk premium to the current low Canada long bond yields would impart a sharp downward bias to current equity cost estimates; use of this method would not be appropriate until long Canada bond yields increase to at least the 4.0% level.