Risk,uncertainty, and leverage

Using mostly theoretical models and traditional risk/uncertainty measures (VIX index, panic, precaution, scary bad news, etc.), the current literature tries to clarify the risk/uncertainty-deleveraging pattern. The findings are not sufficient to explain the dynamic empirical relationship between modern risk/uncertainty indicators and leverage. We fill this gap in the literature by using US quarterly data, from 1985:1 to 2018:4, Granger causality tests, and a structural vector autoregression model. We find that commercial bank leverage rises when geopolitical risk and macroeconomic, policy, and equity uncertainty increase. Client-based business relationships of banks and high government borrowing from banks during crises periods are responsible for this relationship. We find that the leverage of broker-dealers and shadow banks declines when Chicago risk and macroeconomic, policy, financial, and equity uncertainty increase. We argue that the vulnerability of broker-dealers and shadow banks to the risk/uncertainty of the entire market system is responsible for this relationship.     

The contractionary effects of tax shocks on productivity: An empirical and theoretical analysis

I analyze the effects of tax policy changes on US Total Factor Productivity. VAR estimates show that permanent and exogenous tax increases have strong, permanent, and negative effects on TFP which represent about 80% of change in output following the tax increase. I then build a DSGE model which has learning-by-doing and endogenous TFP evolution. The benchmark model is able to replicate the empirical impulse responses. However, when I calibrate the model as in the literature, the effect of taxes on TFP is substantially less elastic than in the data. I argue that this divergence may arise because tax changes labeled as exogenous can give spurious results or because of a mis-specified model.     

Oil commodity returns and macroeconomic factors: A time-varying approach

This paper analyses the dynamic influence of macroeconomic factors on oil commodity returns (crude oil and heating oil) shown in monthly data over the period of 1990–2013. Using a time-varying parameter model via the Kalman filter, we find that macroeconomic factors are relevant for explaining oil commodity returns. We find that multilateral exchange rates have a negative effect on commodity returns. We confirm the existence of a strong linkage between energy and non-energy commodities. More importantly, we find shifts in global demand and SP500 effects that are not identified through the constant parameter model. These variables have had a progressively positive effect on oil commodity returns, especially since 2008.     

Identifying Discretionary Fiscal Policy Reactions with Real‐Time Data

We propose a method of identifying discretionary fiscal policy reactions using real‐time data. Automatic stabilizers should depend on true GDP, while discretionary fiscal policy is contingent on the information that policy makers have in real time. We can compute a real‐time measurement error by comparing the first release of GDP data with later revisions. Discretionary fiscal policy is influenced by this measurement error, whereas automatic fiscal policy is not. We use this identification approach to test the central identifying assumption of Blanchard and Perotti’s (2002) seminal structural vector autoregression (VAR). According to this assumption, fiscal policy makers do not react to GDP developments contemporaneously in a discretionary fashion. We find that government expenditure is adjusted upward if GDP growth in real time is lower than true GDP. This suggests that fiscal policy makers use short‐term funds to buy goods and services in response to their perception of GDP dynamics.     

CO‐INTEGRATING VAR MODELS AND ECONOMIC POLICY

This paper surveys some relevant contributions to the economic literature on co‐integrating vector autoregressive (VAR) models [vector error correction mechanisms (VECMs)], emphasizing their usefulness for economic policy. It further discusses some theoretical aspects that are necessary for a complete understanding of their potential. The theoretical introduction of the co‐integrating VAR model is followed by an illustration of its applications to monetary policy, fiscal policy and exchanges rates as well as in establishing the effects of structural bilateral shocks between countries (the so‐called global VAR, or GVAR, models). Special attention is paid to the VECM capacities of being used in conjunction with dynamic stochastic general equilibrium models and of jointly specifying the short‐ and long‐run dynamics, thus representing the steady‐state of economic systems (by means of the co‐integration relations) and the short‐run dynamics around it.     

关于VaR在风险管理中的研究综述

风险管理技术日益成为金融工程与金融管理领域最重要的研究对象之一,而风险度量技术则是风险管理的核心与基础。只有在准确度量风险暴露头寸的基础上才能更好的进行风险管理。风险测量技术从最早的简单静态的资产-负债管理不断演化发展,时至当下,VaR技术成为最为风靡的风险度量技术。计算VAR的技术方法层出不穷,主要可分为三类:参数法(包括各种正态参数法、加权平均法等);非参数法(包括历史模拟法和蒙特卡洛模拟法);半参数法(包括极值理论等)     

Sequential estimation of a location parameter and powers of a scale parameter from delayed observations

The problem of sequentially estimating a location parameter and powers of a scale parameter is considered in the case when the observations become available at random times. Certain classes of sequential estimation procedures are derived under an invariant balanced loss function and with the observation cost determined by a convex function of the stopping time and the number of observations up to that time.     

基于VAR的RAROC指标评估证券投资基金绩效——实证分析

秉承风险调整收益的理念,将基于VAR构建的RAROC指标用于中国的基金业。在实证过程中对所涉及的相关指标和基金收益率的分布形态等分别进行计算和检验,主要结论是,基金投资组合的非系统性风险没有充分化解;大多数的基金收益率分布形态呈尖峰和右偏,不严格服从正态分布。     

使用粒子群算法解决期权定价模型参数校准问题——以heston模型为例

期权定价模型的参数校准问题是一个常见的难题,以heston 模型为例,定价时需要估计6 个参数,参数估计问题实质上是高维非线性规划问题,由于估参函数的性质不好,一般的估参方法常常失效。使用粒子群（PSO）智能算法可以改善该模型的参数校准问题,因为粒子群算法具有内在随机性,因此参数估计中的局部极小值问题可以被较好地解决。使用2017 年12 月20 日的香港恒生指数期权作为估计样本,并对2017 年12 月25 日的期权进行样本外预测,数值结果表明使用heston 模型对期权进行定价并配合粒子群算法估计参数具有良好的定价效果。     

城乡居民消费结构与产业结构、经济增长关联研究——基于VAR模型的实证分析

运用VAR模型对城乡居民消费结构与产业结构、经济增长的关联性进行了实证分析。研究结果显示,城乡居民消费结构与产业结构、经济增长之间均存在长期均衡关系;经济增长能够促进城乡消费结构的升级,但对农村的促进作用要比城市滞后;城市居民消费结构升级对产业结构升级具有较弱的正向诱导效应,而农村居民消费结构则不具备这种效应。