CAPITAL INFLOWS,FINANCIAL STRUCTURE AND HOUSING BOOMS

We use a panel VAR to study the effect of shocks to capital inflows, which are identified using sign restrictions, on the housing market in OECD countries. To explore how effects of these shocks change with the structure of the mortgage market and the degree of mortgage securitization, we allow the VAR coefficients to vary with mortgage‐market characteristics. Our results indicate that capital‐inflow shocks have a significant and positive effect on real house prices, real credit available to the private sector, and real residential investment. The responses of these variables are stronger in countries with more developed mortgage markets and in countries where securitization is allowed.     

Sign Restrictions,Structural Vector Autoregressions,and Useful Prior Information

This paper makes the following original contributions to the literature. (i) We develop a simpler analytical characterization and numerical algorithm for Bayesian inference in structural vector autoregressions (VARs) that can be used for models that are overidentified, just‐identified, or underidentified. (ii) We analyze the asymptotic properties of Bayesian inference and show that in the underidentified case, the asymptotic posterior distribution of contemporaneous coefficients in an n‐variable VAR is confined to the set of values that orthogonalize the population variance–covariance matrix of ordinary least squares residuals, with the height of the posterior proportional to the height of the prior at any point within that set. For example, in a bivariate VAR for supply and demand identified solely by sign restrictions, if the population correlation between the VAR residuals is positive, then even if one has available an infinite sample of data, any inference about the demand elasticity is coming exclusively from the prior distribution. (iii) We provide analytical characterizations of the informative prior distributions for impulse‐response functions that are implicit in the traditional sign‐restriction approach to VARs, and we note, as a special case of result (ii), that the influence of these priors does not vanish asymptotically. (iv) We illustrate how Bayesian inference with informative priors can be both a strict generalization and an unambiguous improvement over frequentist inference in just‐identified models. (v) We propose that researchers need to explicitly acknowledge and defend the role of prior beliefs in influencing structural conclusions and we illustrate how this could be done using a simple model of the U.S. labor market.     

OIL AND THE MACROECONOMY: A QUANTITATIVE STRUCTURAL ANALYSIS

We model an open economy where macroeconomic variables fluctuate in response to oil supply shocks, as well as aggregate demand and supply shocks generated domestically and abroad. We use several robust predictions of the model to identify five fundamental shocks underlying the fluctuations of the (real) oil price, the US activity and the global business cycle. The estimates show that supply shocks generated in the global economy explain the largest fraction of the oil price fluctuations, about four times more than canonical oil supply shocks. The correlation between oil prices and the US activity varies with the type of shock.     

SHOCKING STUFF: TECHNOLOGY,HOURS, AND FACTOR SUBSTITUTION

The response of hours to technology shocks is a key controversy in macroeconomics. We show that differences between RBC and NK models hinge on highly restrictive views of technology. We introduce CES production technologies and demonstrate that the response of hours depends on the factor‐augmenting nature of shocks and the capital–labor substitution elasticity in both models. We develop analytical expressions to establish the thresholds determining its sign. This opens new margins for shock identification combining theory and VAR evidence. We discuss how our models provide new robust restrictions for empirical work, especially using the labor income share.     

国际原油价格系统结构性突变识别与分析

选取1997年至2011年作为样本区间,以国际原油市场结构的周期性和突变特征作为研究对象,在筛选变量的基础上,以原油的价格、供应、需求、美元指数和中国原油净进口为内生变量,以库存和投机因素为外生变量,建立原油市场结构经验VARX模型,分析各变量对原油价格的影响,并以此为基础建立基于Bayes理论的原油价格系统MSBVAR模型,识别和分析原油价格系统在考察期内的结构性变化。研究结果表明,影响原油价格波动的首要因素为中国原油净进口,存在亚洲溢价现象且持续期为2个多季度,美元指数影响次之,之后是原油需求,原油供应的贡献率影响最小;原油价格的翘尾效应在不同状态下的滞后期均为1个季度,且效应显著。突发事件对原油价格系统均衡结构的冲击不可忽视,1997年至2011年国际原油市场只存在一个结构突变点,即美国金融危机是导致该次原油价格系统结构平衡被打破的唯一事件。     

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。     

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。     

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。     

Identification in Differentiated Products Markets Using Market Level Data

We present new identification results for nonparametric models of differentiated products markets, using only market level observables. We specify a nonparametric random utility discrete choice model of demand allowing rich preference heterogeneity, product/market unobservables, and endogenous prices. Our supply model posits nonparametric cost functions, allows latent cost shocks, and nests a range of standard oligopoly models. We consider identification of demand, identification of changes in aggregate consumer welfare, identification of marginal costs, identification of firms' marginal cost functions, and discrimination between alternative models of firm conduct. We explore two complementary approaches. The first demonstrates identification under the same nonparametric instrumental variables conditions required for identification of regression models. The second treats demand and supply in a system of nonparametric simultaneous equations, leading to constructive proofs exploiting exogenous variation in demand shifters and cost shifters. We also derive testable restrictions that provide the first general formalization of Bresnahan's (1982) intuition for empirically distinguishing between alternative models of oligopoly competition. From a practical perspective, our results clarify the types of instrumental variables needed with market level data, including tradeoffs between functional form and exclusion restrictions.     

CAN LONG‐RUN RESTRICTIONS IDENTIFY TECHNOLOGY SHOCKS?

Galí's innovative approach of imposing long‐run restrictions on a vector autoregression (VAR) to identify the effects of a technology shock has become widely utilized. In this paper, we investigate its reliability through Monte Carlo simulations using calibrated business cycle models. Overall, Galí's methodology appears to be fruitful: the impulse responses derived from the artificial data generally have the same sign and qualitative pattern as the true responses, and the approach can be informative in discriminating between alternative models. However, our results reveal some important quantitative shortcomings, including considerable estimation uncertainty about the impact of technology shocks on macroeconomic variables. More generally, the conditions under which the methodology performs well appear considerably more restrictive than implied by the key identifying assumption. This underscores the importance of using economic models to guide in the implementation of the approach, in interpreting the results, and in assessing its limitations. (JEL: C32, E32, O33)     

A COMPARISON OF THE EFFECTS OF EXOGENOUS OIL SUPPLY SHOCKS ON OUTPUT AND INFLATION IN THE G7 COUNTRIES

A comparison of the effects of exogenous shocks to global crude oil production on seven major industrialized economies suggests a fair degree of similarity in the real growth responses. An exogenous oil supply disruption typically causes a temporary reduction in real GDP growth that is concentrated in the second year after the shock. Inflation responses are more varied. The median CPI inflation response peaks after three to four quarters. Exogenous oil supply disruptions need not generate sustained inflation or stagflation. Typical responses include a fall in the real wage, higher short‐term interest rates, and a depreciating currency with respect to the dollar. Despite many qualitative similarities, there is strong statistical evidence that the responses to exogenous oil supply disruptions differ across G7 countries. For suitable subsets of countries, homogeneity cannot be ruled out. A counterfactual historical exercise suggests that the evolution of CPI inflation in the G7 countries would have been similar overall to the actual path even in the absence of exogenous shocks to oil production, consistent with a monetary explanation of the inflation of the 1970s. There is no evidence that the 1973–1974 and 2002–2003 oil supply shocks had a substantial impact on real growth in any G7 country, whereas the 1978–1979, 1980, and 1990–1991 shocks contributed to lower growth in at least some G7 countries. (JEL: E31, E32, Q43)     

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.     

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。     

EVALUATING THEORIES OF BANK RUNS WITH HETEROGENEITY RESTRICTIONS

This paper empirically tests theories of bank runs. We use a structural panel VAR to extract runs from deposit market data. Identification exploits cross‐sectional heterogeneity in deposit insurance: we identify bank runs as adverse deposit market supply shocks hitting uninsured banks harder compared to insured. Conditional on a run, we study the behavior of uninsured banks with bad and good fundamentals. We find that both experience runs, but deposit outflows at the former are more severe. Panic effects, which affect all uninsured deposits alike, irrespective of fundamentals, dominate in the aggregate. Insured banks partially absorb the outflow of uninsured deposits.     

WHY ARE THE 2000s SO DIFFERENT FROM THE 1970s? A STRUCTURAL INTERPRETATION OF CHANGES IN THE MACROECONOMIC EFFECTS OF OIL PRICES

In the 1970s, large increases in the price of oil were associated with sharp decreases in output and large increases in inflation. In the 2000s, even larger increases in the price of oil were associated with much milder movements in output and inflation. Using a structural VAR approach, Blanchard and Gali (in J. Gali and M. Gertler (eds.) 2009, International Dimensions of Monetary Policy, University of Chicago Press, pp. 373–428) argued that this reflected a change in the causal relation from the price of oil to output and inflation. They then argued that this change could be due to a combination of three factors: a smaller share of oil in production and consumption, lower real wage rigidity, and better monetary policy. Their argument, based on simulations of a simple new‐Keynesian model, was informal. Our purpose in this paper is to take the next step, and to estimate the explanatory power and contribution of each of these factors. To do so, we use a minimum distance estimator that minimizes, over the set of structural parameters and for each of two samples (pre‐ and post‐1984), the distance between the empirical SVAR‐based impulse response functions and those implied by a new‐Keynesian model. Our empirical results point to an important role for all three factors.     

DO HOUSE PRICES DRIVE CONSUMPTION GROWTH? THE COINCIDENT CYCLES OF HOUSE PRICES AND CONSUMPTION IN THE UK

This paper uses a realistic structural lifecycle model of consumption and housing decisions to understand how data might distinguish different mechanisms that explain the correlation between house prices and consumption. The model includes price and earnings shocks estimated from data (the latter including aggregate and idiosyncratic components), and incorporates realistic features of the UK mortgage market. We simulate the model using more than 30 years of realized shocks and under counterfactual scenarios. Our results confirm the intuition of earlier studies: house price shocks should have a larger effect on the consumption of older households and earnings shocks on young households.     

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.     

信息不对称下价格随机的应急数量折扣契约研究

以市场需求和市场价格随机波动的二级供应链为研究对象,寻找其在信息不对称条件下绩效优化的路径。通过显示原理分别构建生产成本和销售成本信息不对称时应急供应链的数量折扣契约模型,得到最优订货量与最佳批发价策略。通过具体的算例加以验证,分析了信息不对称程度对供应链上成员及整个供应链绩效的影响。研究结果表明：当突发事件造成市场价格随机波动和市场需求变化时,供应链上的跟随者能从隐瞒私人信息中获利。但当市场需求增大时,整个供应链绩效受损,反之则反是。这与以往研究在市场需求随机、市场价格固定和信息不对称条件下的结论迥异。     

中国原油期货动态风险溢出研究

本文首次量化分析了我国原油期货与国际基准原油、上证指数以及人民币汇率之间的风险溢出关系。通过构建收益率和波动率的静态和动态网络,本文对我国原油期货与国内外市场之间的信息流向的强度、方向和动态性进行了初步的探索。研究发现,我国上市的原油期货与国际基准原油之间的信息关联密切,与股票市场以及汇率市场之间的关系相对较弱。同时,在构建的原油-股票-汇率系统中,我国原油期货处于信息的接收方,国际油价波动信息对我国原油期货市场存在明显的正向冲击作用。     

随机需求下考虑不同竞争情形的网约车平台动态定价

针对乘车需求波动下网约车平台间存在乘车需求竞争和乘运供应竞争的最优定价问题，以平台期望收益最大化为目标，运用最优控制论方法，构建不同竞争情形下的网约车平台动态定价模型，并利用哈密尔顿函数及模型推导，求得最优动态竞争价格解以及乘运供应率与需求率的变化轨迹。结果表明：平台最优动态竞争价格随市场需求的波动而动态变化，且最优价格可以有效调控平台供应能力，促使平台供需匹配，优化平台期望收益。此外，乘车需求市场竞争越激烈，平台最优价格越低，而乘运供应市场竞争越激烈，最优价格越高。平台间竞争的加剧将降低平台的期望收益，且平台期望收益随着固定佣金报酬率的提高先增大后减小。