Stochastic Models of Implied Volatility Surfaces

We propose a market–based approach to the modelling of implied volatility, in which the implied volatility surface is directly used as the state variable to describe the joint evolution of market prices of options and their underlying asset. We model the evolution of an implied volatility surface by representing it as a randomly fluctuating surface driven by a finite number of orthogonal random factors. Our approach is based on a Karhunen–Loeve decomposition of the daily variations of implied volatilities obtained from market data on SP500 and DAX options.
We illustrate how this approach extends and improves the accuracy of the well–known 'sticky moneyness' rule used by option traders for updating implied volatilities. Our approach gives a justification for the use of 'Vegas' for measuring volatility risk and provides a decomposition of volatility risk as a sum of independent contributions from empirically identifiable factors.
(J.E.L.: G130, C14, C31).     

Stochastic Volatility: Likelihood Inference and Comparison with ARCH Models

In this paper, Markov chain Monte Carlo sampling methods are exploited to provide a unified, practical likelihood-based framework for the analysis of stochastic volatility models. A highly effective method is developed that samples all the unobserved volatilities at once using an approximating offset mixture model, followed by an importance reweighting procedure. This approach is compared with several alternative methods using real data. The paper also develops simulation-based methods for filtering, likelihood evaluation and model failure diagnostics. The issue of model choice using non-nested likelihood ratios and Bayes factors is also investigated. These methods are used to compare the fit of stochastic volatility and GARCH models. All the procedures are illustrated in detail.     

Empirical Evidence of the Leverage Effect in a Stochastic Volatility Model: A Realized Volatility Approach

Increasing attention has been focused on the analysis of the realized volatility, which can be treated as a proxy for the true volatility. In this paper, we study the potential use of the realized volatility as a proxy in a stochastic volatility model estimation. We estimate the leveraged stochastic volatility model using the realized volatility computed from five popular methods across six sampling-frequency transaction data (from 1-min to 60- min) based on the trust region method. Availability of the realized volatility allows us to estimate the model parameters via the MLE and thus avoids computational challenge in the high dimensional integration. Six stock indices are considered in the empirical investigation. We discover some consistent findings and interesting patterns from the empirical results. In general, the significant leverage effect is consistently detected at each sampling frequency and the volatility persistence becomes weaker at the lower sampling frequency.     

Semi-Parametric Comparison of Stochastic Volatility Models using Realized Measures

This paper proposes a procedure to test for the correct specification of the functional form of the volatility process within the class of eigenfunction stochastic volatility models. The procedure is based on the comparison of the moments of realized volatility measures with the corresponding ones of integrated volatility implied by the model under the null hypothesis.
We first provide primitive conditions on the measurement error associated with the realized measure, which allow to construct asymptotically valid specification tests.
Then we establish regularity conditions under which the considered realized measures, namely, realized volatility, bipower variation, and modified subsampled realized volatility, satisfy the given primitive assumptions.
Finally, we provide an empirical illustration based on three stocks from the Dow Jones Industrial Average.     

Estimation of Asymmetric Stochastic Volatility Models for Stock-Exchange Index Returns

The objective of this paper is to put forward a new autoregressive asymmetric stochastic volatility model for modeling volatility and to compare results obtained for this model with an autoregressive stochastic model and another asymmetric volatility model, such as, asymmetric generalized autoregressive conditional heteroskedasticity model. The results obtained from the estimation by maximum likelihood have shown the volatility behavior is asymmetric in the majority of cases. This fact is better shown by the ARSVA model, than the rest of alternative models. Moreover, the ARSVA model is able to reproduce other stylized facts of such series, such as high kurtosis, no autocorrelation of returns, slow decreasing of the autocorrelation function of the squared returns and high persistence.

Interest Rate Volatility Regimes in Selected Asian Countries: A Univariate Markov Switching Analysis

Business cycle dynamics are determined by relatively large volatilities in output,consumption,and investment,which leads to cyclical fluctuations in interest rates.Using the Markov switching model,we model the nominal interest rate movements to explain the volatility regime shifts in a set of selected emerging Asian economies.The estimated results provide significant evidence of regime-dependent means,variances,and probabilities in both stable and volatile regimes in selected countries,confirming the existence of two distinct regimes in nominal interest rate movements.In addition,the smoothed probability results of switching autoregressive model show that the model is capable of capturing the two regimes for the corresponding nominal interest rate behaviors.Besides,the results reveal that the stables regimes have higher durations than the volatile regimes.This study also shows the advantage of Markov switching models over conventional regression models,allowing the identification of different regimes for the cyclical behavior of interest rates.     

过剩产能与通货膨胀的关系分析——基于包含随机波动的TVP模型考察

为了更准确的考察目前中国的过剩产能与通货膨胀的关系,本文构造了一个包含随机波动的TVP模型对中国通货膨胀与产出缺口间的关系进行了实证分析,实证结果表明:中国通货膨胀的随机波动程度有不断增强的趋势;产出缺口对通货膨胀的影响力度有不断减弱的趋势;改善经济发展的结构性矛盾、提高供给部门的效率是实现价格稳定下经济快速增长的根本途径.     

Exchange Rate Volatility and Output Volatility: A Theoretical Approach*

This paper makes an attempt to determine the factors influencing exchange rate and exchange rate uncertainty, as well as output and output variability. In the context of a small open economy under flexible exchange rates regime it is found that the level both of exchange rate and output is affected by monetary and inflationary shocks, as well as shocks in government spending, output, and trade balance. Further, the uncertainty of exchange rate and output is associated positively with the uncertainty of all shocks while the contemporaneous occurrence of selected shocks imposes either a positive or negative impact on exchange rate and output volatility. Finally, it is shown that the effect of the determinants either of exchange rate volatility or output volatility is very sensitive to the parameter values.     

Volatility equicorrelation: A cross-market perspective

This paper contains the first empirical application of the Dynamic Equicorrelation (DECO) model to a cross-market dataset composed of equities, bonds, foreign exchange rates and commodities during 1983–2013. The originality of our approach consists of examining the volatility equicorrelations, by updating the concept of ‘volatility surprise’. We document that the average volatility equicorrelation across markets is around 15%, while being time-varying with regime shifts before/after September 2005 and with a low mean-reversion level.     

交易冲击与资产的非对称波动：基于“已实现波动率”

采用日内“已实现波动率”测度，本文从交易冲击的角度对中国A、B股的目内波动特征进行研究。结果表明，已实现波动率可以很好捕捉我国股市波动的非对称效应。而且这种非对称波动存在显著的时变特征；交易行为能够解释A股的非对称效应．但B股的非对称波动还存在其他的影响因素；知情交易降低了波动性，不知情交易则增强了波动性；结合“处置效应”对波动非对称性的更深入考察以及稳健性检验的都支持了我们的经验发现。     

Volatility and growth: Governments are key

There exists a persistent disagreement in the literature over the effect of business cycles on economic growth. This paper offers a solution to this disagreement, suggesting that volatility carries not only a positive direct effect, but also a negative indirect effect, operating through the insurance mechanism of government size. Theoretically, the net growth effect of volatility is then ambiguous. The paper reveals the underlying endogeneity of government size in a balanced panel of 90 countries from 1961 to 2010. In practice, the negative indirect channel dominates in democracies, but with less power to choose public services in autocratic regimes the positive direct effect takes over. Consequently, volatile growth rates are detrimental to growth in democracies, but beneficial to growth in autocracies. The empirical results suggest that a one standard deviation increase of volatility lowers growth by up to 0.52 percentage points in a democracy, but raises growth by 1.66 percentage points in a total autocracy. These findings point to a crucial intermediating role of governments in the relationship between volatility and growth. Both the size of the public sector and the regime form assume key roles.     

Aid, Volatility, and Growth Again: When Aid Volatility Matters and When it Does Not

In previous papers the authors have argued that aid is likely to mitigate the negative effects of external shocks on economic growth (i.e. that aid is more effective in countries which are more vulnerable to external shocks). Recently an important debate has emerged about the possible negative effects of aid volatility itself. However, the cushioning effect of aid may involve some volatility in aid flows, which then is not necessarily negative for growth. In this paper the authors examine to what extent the time profile of aid disbursements may contribute to an increase or a decrease of aid effectiveness. They first show that aid, even if volatile, is not clearly as pro-cyclical as is often argued, and, even if pro-cyclical, is not necessarily destabilizing. They measure aid volatility by several methods and assess pro-cyclicality of aid with respect to exports, thus departing from previous literature, which usually assess pro-cyclicality of aid with respect to national income or fiscal receipts. The stabilizing/destabilizing nature of aid is measured by the difference in the volatility of exports and the volatility of the aid plus export flows. Then, in order to take into account the diversity of shocks to which aid can respond, they consider the effect of aid on income volatility and again find that aid is making growth more stable, while its volatility reduces this effect. They finally show through growth regressions that the higher effectiveness of aid in vulnerable countries is to a large extent due to its stabilizing effect.     

我国财政支出波动对居民消费波动的影响研究

利用1981—2010年我国27个省级地区的面板数据,在加入居民收入波动、金融发展水平、贸易开放度三个控制变量的基础上,综合运用固定效应模型及工具变量估计法,对我国财政支出波动与居民消费波动的关系进行探讨,结果表明:居民消费波动受财政支出波动的影响显著,两者呈正相关关系;金融发展水平及贸易开放度有助于减轻居民消费的波动程度;居民收入波动对消费波动的影响不显著。     

Income Inequality and Macroeconomic Volatility: An Empirical Investigation

We explore the impact of macroeconomic volatility on the distribution of income. Using a cross‐section of developed and developing countries, we find that greater output volatility, defined as the standard deviation of the rate of output growth, is associated with a higher Gini coefficient and income share of the top quintile. The coefficients suggest that a strong effect on inequality resulting from a reduction in volatility: the Gini coefficient of a country like Chile would fall by 6 points if it were to reduce its volatility to the same level as Sweden or Norway. Our results seem not to be driven by the high‐inequality/high‐volatility Latin American countries.     

Volatility and firm growth

A growing body of macroeconomic evidence suggests that volatility is detrimental for economic growth. The channel through which this materializes, however, is less clear. Moreover, substantive evidence based on disaggregate data is scarce. In this paper, we provide empirical support for this relationship using a detailed cross-country firm-level dataset. We also provide additional evidence that institutional obstacles magnify the adverse effect of perceived volatility on firm growth.      

Modeling Exchange Rate Volatility

This paper investigates the impact of the volatility of the underlying macroeconomic fundamentals on exchange rate volatility utilizing the bounds testing approach to cointegration. The results show that, in the long run the volatility of the money supply is the sole determinant, whereas in the short run overshooting is found.     

Stochastic growth: asymptotic distributions

Summary. This note studies conditions under which sequences of state variables generated by discrete-time stochastic optimal accumulation models have law of large numbers and central limit properties. Productivity shocks with unbounded support are considered. Instead of restrictions on the support of the shock, an “average contraction” property is required on technology. Received: August 27, 2001; revised version: January 9, 2002 RID="*" ID="*"The author thanks John Creedy and Rabee Tourky for helpful comments, and the Economic Theory Center, University of Melbourne for financial support.