石油价格冲击与中国实际经济波动研究——基于开放RBC模型的分析

中国的石油对外贸易依存度较高,国际油价波动这种外部冲击对经济可能产生各种影响。本文构建了开放经济条件下的RBC(真实经济周期)模型,通过引入石油价格冲击和技术冲击,解释了中国实际经济波动的特征事实,并探讨了石油价格冲击对于中国实际经济波动的作用机制。相较于已有研究,该模型更好地模拟了中国主要宏观经济变量的波动特征。同时,研究发现,除贸易余额冲击外,石油价格冲击对经济也产生负向影响。因此,能源价格改革应遵循循序渐进的原则,防范石油价格波动对实际经济产生较大冲击。     

WHY AGNOSTIC SIGN RESTRICTIONS ARE NOT ENOUGH: UNDERSTANDING THE DYNAMICS OF OIL MARKET VAR MODELS

Sign restrictions on the responses generated by structural vector autoregressive models have been proposed as an alternative approach to the use of exclusion restrictions on the impact multiplier matrix. In recent years such models have been increasingly used to identify demand and supply shocks in the market for crude oil. We demonstrate that sign restrictions alone are insufficient to infer the responses of the real price of oil to such shocks. Moreover, the conventional assumption that all admissible models are equally likely is routinely violated in oil market models, calling into question the use of posterior median responses to characterize the responses to structural shocks. When combining sign restrictions with additional empirically plausible bounds on the magnitude of the short‐run oil supply elasticity and on the impact response of real activity, however, it is possible to reduce the set of admissible model solutions to a small number of qualitatively similar estimates. The resulting model estimates are broadly consistent with earlier results regarding the relative importance of demand and supply shocks for the real price of oil based on structural vector autoregressive (VAR) models identified by exclusion restrictions, but imply very different dynamics from the posterior median responses in VAR models based on sign restrictions only.     

Modeling Price Volatility Based on a Genetic Programming Approach

Business profitability is highly dependent on risk management strategies to hedge future cash flow uncertainty. Commodity price shocks and fluctuations are key risks for companies with global supply chains. The purpose of this paper is to show how artificial intelligence (AI) techniques can be used to model the volatility of commodity prices. More specifically, the authors introduce a new model – LIQ‐GARCH – that uses genetic programming to forecast volatility. The newly generated model is then used to forecast the volatility of the following three indexes: the Commodity Research Bureau (CRB) index, the West Texas Intermediate (WTI) oil futures prices and the Baltic Dry Index (BDI). The empirical model performance tests show that the newly generated model in this paper is considerably more accurate than the traditional GARCH model. As a result, this model can help businesses to design optimal risk management strategies and to hedge themselves against price uncertainty.     

石油价格冲击与经济波动风险最小化的货币供应机制分析

本文通过构建一个包含石油价格冲击的DSGE模型,基于经济波动风险的最小化,研究了石油价格冲击对中国货币供应机制的影响。在模型结构参数贝叶斯估计的基础上,通过货币政策前沿的比较分析,回答了中国货币供应机制是否应该对石油价格冲击做出反应以及应该如何反应的政策问题。研究结果表明,中国当前的货币供应机制并没有对石油价格冲击做出显著的反应,但为了减小经济波动的风险,中国的货币供应机制在对产出增长和通货膨胀反应的同时,对石油价格冲击做出反应具有必要性。     

不同突发事件下进口原油采购策略

石油对经济生活的重要性不言而喻,中国原油的高对外依存度及集中的进口来源区域引起我们对能源安全的广泛关注,如何有效最小化国际原油价格波动和供应短缺或中断带来的风险,制定突发事件影响下的最佳采购策略是我们必需关注的焦点,但目前结合突发事件的采购策略研究还不足。论文通过采用符合中国原油进口习惯的月度数据,建立了突发事件下的CVaR模型,综合考虑价格波动、供应中断造成的GDP冲击和战略石油储备因素,分析三种不同突发事件情景下的原油进口采购策略。研究表明：当预期中东区域出现危机时,非洲和欧洲/俄罗斯是增加采购量的理想选择,若迪拜价格波动不剧烈,亚太采购量也可适当增加;对于仅仅只有价格变动,动用战略石油储备降低风险有限,只有当供给中断时,动用战略储备才能发挥巨大的降低风险,更好的减少对国民经济冲击的作用。本文在最小化原油进口风险值且同时考虑进口来源多样化、风险、成本及价格变动率的情况下,构建的基于CVaR的应急原油进口采购策略模型,丰富了该领域的研究成果,为中国原油进口采购策略提供了具体可操作的参考。     

THE INTERNATIONAL DIMENSION OF PRODUCTIVITY AND DEMAND SHOCKS IN THE US ECONOMY

This paper analyzes the cross‐country effects of productivity and demand disturbances in the United States identified with sign restrictions based on standard theory. Productivity gains in US manufacturing increase US consumption and investment vis‐à‐vis foreign countries, resulting in a trade deficit and higher international prices of US goods, despite the rise in their supply. Financial adjustment works via a higher global value of US equities, real dollar appreciation, and an expansion of US gross foreign liabilities as well as assets. Positive demand shocks to US manufacturing also increase investment and cause a real dollar appreciation, but have limited effects on the trade balance and net foreign assets. Our findings emphasize the importance for macroeconomic interdependence of endogenous fluctuations in aggregate demand across countries in response to business cycle shocks.     

供给与需求驱动型原油价格变动对股票市场的多时间尺度影响研究

不同时间尺度下，供给和需求驱动型原油价格变动对股票市场的影响具有差异性，本文结合小波变化及向量自回归模型，从影响方向、影响强度及影响持续时间三个角度对这种差异性展开研究。首先，在多时间尺度下识别供给和需求驱动型原油价格变动；随后，就不同类型原油价格变动对全球综合股指的动态影响进行分析。结果发现：1）两类原油价格变动对股票市场在短、中及长期下均有显著影响，但需求驱动型原油价格变动在超短期（尺度1：2-4个月）和超长期（尺度6：64-128个月）下对股票市场没有显著影响；2）两类原油价格变动对股票市场的影响方向在短期和中期下具有随机性，在长期下具有正向影响；3）两类原油价格变动对股票市场的影响强度在短期和中期较在长期要高出至少60%；4）两类原油价格变动对股票市场的影响时间随着时间尺度的增长而增长，由短期下的20个月左右延长至长期下的60个月以上。     

UNINSURED COUNTERCYCLICAL RISK: AN AGGREGATION RESULT AND APPLICATION TO OPTIMAL MONETARY POLICY

We consider an incomplete markets economy with capital accumulation and endogenous labor supply. Individuals face countercyclical idiosyncratic labor and asset risk. We derive conditions under which the aggregate allocations and price system can be found by solving a representative agent problem. This result is applied to analyze the properties of an optimal monetary policy in a New Keynesian economy with uninsured countercyclical individual risk. The optimal monetary policy that emerges from our incomplete markets economy is the same as the optimal monetary policy in a representative agent model with preference shocks. When price rigidity is the only friction the optimal monetary policy calls for stabilizing the inflation rate at zero.     

国际油价、美国经济不确定性和中国股市的波动溢出效应研究

2008年金融危机以来的全球股市震荡,油价波动剧烈和经济的不确定性使得研究不同市场间的风险传导效应具有重要的意义。在综合评价现有研究的缺陷和既有改进方法的情况后,本文借鉴Diebold and Yilmaz （2012）的研究方法探索国际原油价格、美国经济不确定性和中国股市的波动溢出效应。本文选取1986年1月到2016年12月原油价格、美国经济不确定性指数和中国股票价格的月度数据,分别研究了静态波动溢出指数,动态波动溢出指数并做出了非线性检验。实证结果表明：变量国际油价解释了大部分的波动。方向性溢出指数是双向的和非对称的。在整个样本阶段系统的波动主要来自其他变量的冲击,变量国际油价的溢出效应占比重较大。变量国际油价、美国经济不确定性和中国股价对其他变量的波动溢出都存在非线性效应,前两者的正向变量的溢出效应较大,负向变量的溢出效应较小;后者的正向变量的溢出效应较小,负向变量的溢出效应较大。     

Firms,Destinations, and Aggregate Fluctuations

This paper uses a data base covering the universe of French firms for the period 1990–2007 to provide a forensic account of the role of individual firms in generating aggregate fluctuations. We set up a simple multisector model of heterogeneous firms selling to multiple markets to motivate a theoretically founded decomposition of firms' annual sales growth rate into different components. We find that the firm‐specific component contributes substantially to aggregate sales volatility, mattering about as much as the components capturing shocks that are common across firms within a sector or country. We then decompose the firm‐specific component to provide evidence on two mechanisms that generate aggregate fluctuations from microeconomic shocks highlighted in the recent literature: (i) when the firm size distribution is fat‐tailed, idiosyncratic shocks to large firms directly contribute to aggregate fluctuations, and (ii) aggregate fluctuations can arise from idiosyncratic shocks due to input–output linkages across the economy. Firm linkages are approximately three times as important as the direct effect of firm shocks in driving aggregate fluctuations.     

重大供给冲击对石油市场的影响分析

收集历史上石油市场的重大供给冲击事件,包括委内瑞拉大罢工、伊拉克战争、卡特琳娜飓风、土耳其攻打库尔德、墨西哥湾漏油事件和利比亚战争,选取Brent、WTI现货和期货以及迪拜和阿曼现货等国际主要石油市场数据,建立GARCH模型,分析供给冲击对市场波动性的影响,进一步采用异方差修正的事件分析法考察这些事件对全球主要石油市场收益率的短期影响。研究结果表明,大部分事件会导致事件窗内的方差变大,除伊拉克战争和墨西哥湾漏油事件外,其他事件的事件窗内的累计超额收益显著为正,同一事件下所有市场事件窗内累计超额收益走势一致,重大事件发生的地理区位对邻近市场的收益率的影响更大。对实证结果进行经济解释,针对不同的石油市场参与者给出相应的政策建议。     

THE INTERNATIONAL TRANSMISSION OF VOLATILITY SHOCKS: AN EMPIRICAL ANALYSIS

This paper proposes an empirical model which can be used to estimate the international transmission of volatility shocks. Using this model we estimate that a one standard deviation increase in the volatility of the shock to US real GDP leads to a decline in UK GDP of 1% relative to trend and a 0.7% increase in UK CPI relative to trend at the two‐year horizon. Using a nonlinear open‐economy DSGE model, we find that these empirical estimates are consistent with the response to a perturbation to the volatility of foreign “supply” type shocks, while an increase in the volatility of demand shocks has a negligible impact.     

基于VAR模型的油价波动对我国经济影响分析

本文运用VAR模型,构建了原油价格与经济增长、物价水平、货币政策、失业率之间的动态关系系统,着重探讨油价波动对我国一些重要经济变量,特别是经济增长的影响规律。Granger因果关系分析表明,油价波动是引起经济增长率、物价水平、货币政策等经济指标变化的Granger原因。通过VAR(2)模型及脉冲响应分析,油价上升对我国经济的主要影响有:不会使国内生产总值减少,但会使经济增长速度变缓;通过对总需求的拉动及成本增加这样两条途径使物价水平上升;长期内会使失业率增加;增加了有效实施货币政策的难度。整体来看,尽管国际油价及我国的经济变量复杂多变,由国际油价、经济增长、物价水平、货币供应量、失业率这五个变量所构成的经济系统是稳定的,也就是说,通过市场经济的自动调节和政府的宏观经济调控,我国的经济能够平稳有序的发展。     

货币政策规则对国际资本流动与人民币汇率的时变影响——基于TVP-SV-VAR模型的实证检验

本文从货币政策理论出发,构建以稳定国际资本流动与人民币汇率的“多目标”货币政策规则理论模型,并采用1998年1月至2019年11月的月度数据,建立开放经济下的TVP-SV-VAR模型,实证检验不同货币政策规则下货币供应冲击、利率冲击对国际资本流动与人民币汇率的时变与动态影响。结果表明：(1)不同时间阶段,货币政策冲击对国际资本流动和人民币汇率的影响存在较强的时变特征。(2)等间隔脉冲响应表明,货币政策冲击对国际资本流动的短期影响效应要高于中长期,而对人民币汇率的影响却存在一定滞后性和扩散性,且价格型规则更有利于熨平外部冲击对国际资本流动与人民币汇率的影响。(3)时点脉冲响应表明,利率冲击对国际资本流动和人民币汇率的影响弱于货币供应冲击,且利率冲击对国际资本流动的影响回到稳态均衡的速度更快。总体来看,在调节国际资本流动和稳定人民币汇率的效果上,价格型规则优于数量型规则,我国央行货币政策选择应逐步从数量型规则向价格型规则转变。     

Sticky Price Models of the Business Cycle: Can the Contract Multiplier Solve the Persistence Problem?

We construct a quantitative equilibrium model with firms setting prices in a staggered fashion and use it to ask whether monetary shocks can generate business cycle fluctuations. These fluctuations include persistent movements in output along with the other defining features of business cycles, like volatile investment and smooth consumption. We assume that prices are exogenously sticky for a short time. Persistent output fluctuations require endogenous price stickiness in the sense that firms choose not to change prices much when they can do so. We find that for a wide range of parameter values, the amount of endogenous stickiness is small. Thus, we find that in a standard quantitative model, staggered price‐setting, alone, does not generate business cycle fluctuations.     

COLLATERAL CONSTRAINTS IN A MONETARY ECONOMY

This paper reviews the role of collateral constraints in transforming small monetary shocks into large persistent output fluctuations. We do this by introducing money in the heterogeneous‐agent real economy of Kiyotaki and Moore (1997). Money enters in a cash‐in‐advance constraint and money supply is managed via open‐market operations. We find that a monetary shock generates persistent movements in aggregate output, the amplitude of which depends upon whether or not debt contracts are indexed. If only nominal contracts are traded, money shocks can trigger large output fluctuations. In this case a money expansion triggers a boom, whereas money contractions generate recessions. In contrast, if contracts are indexed then amplification is not only smaller; it can also generate the reverse results. When the possibility of default and renegotiation is considered, the model can generate asymmetric business cycles with recessions milder than booms. Finally, monetary shocks generate a highly persistent dampening cycle rather than a smoothly declining deviation. (JEL: E32, E43, E44, E52)     

FINANCIAL FRAGILITY,LIQUIDITY, AND ASSET PRICES

We define a financial system to be fragile if small shocks have disproportionately large effects. In a model of financial intermediation, we show that small shocks to the demand for liquidity cause either high asset‐price volatility or bank defaults or both. Furthermore, as the liquidity shocks become vanishingly small, the asset‐price volatility is bounded away from zero. In the limit economy, with no shocks, there are many equilibria. However, if banks face idiosyncratic liquidity shocks, then the only equilibria that are robust to the introduction of small aggregate risk involve stochastic consumption as well as volatile asset, prices. (JEL: D5, D8, G2)     

OPTIMAL MONETARY POLICY AND FINANCIAL STABILITY IN A NON‐RICARDIAN ECONOMY

I present a model with discontinuous asset‐market participation (DAMP), where all agents are non‐Ricardian, and where heterogeneity among market participants implies financial‐wealth effects on aggregate consumption. The implied welfare criterion shows that financial stability arises as an additional and independent target, besides inflation and output stability. Evaluation of optimal policy under discretion and commitment reveals that price stability may no longer be optimal, even absent inefficient supply shocks: some fluctuations in output and inflation may be optimal as long as they reduce financial instability. Ignoring the heterogeneity among market participants may lead monetary policy to induce substantially higher welfare losses.     

货币供应量传导研究——基于新凯恩斯DSGE模型的研究

本文以新凯恩斯主义理论为基础,通过构建一个动态随机一般均衡模型(DSGE),考察了不同粘性下货币供应量冲击在我国经济中的传导。采用了贝叶斯方法估计DSGE模型的参数,并运用脉冲响应分析冲击的传导。研究发现,DSGE模型对中国的经济数据拟合较好,可以用来分析中国的经济问题;投资在货币供应量冲击的传导中发挥着重要作用,消费的传导作用较小;在估计的模型参数的基础上,受约束的仿真实验说明单一名义粘性不改变冲击的传导途径,尽管在单一名义粘性情形下,产出、通胀等对冲击的响应与双粘性情形时有所不同。     

石油储备价值研究:基于供应链视角

石油储备是应对石油供应链危机的重要途径.构建了反映石油供应链运营的线性规划模型,利用该模型模拟供应链发生不同程度的供应危机和价格危机时,30 d、60 d和90 d的石油储备在应对需求及价格危机中的作用.研究结果表明:当需求及价格发生较大幅度上升时,供应链石油储备可以有效抑制需求及价格上升引起的运作成本上涨,且不同规模...