情绪波动和资产价格波动

投资者的情绪波动对于理解资产价格的波动有着重要的意义 ,但是已有研究对情绪波动的刻画还过于简单。本文在Mehra和Sah( 2 0 0 2 )对情绪波动研究的基础之上 ,更加全面地描述了投资者情绪波动 ,使用风险规避系数、跨期替代弹性和主观贴现因子三个投资者主观偏好参数的波动来描述投资者情绪波动。本文研究了情绪波动对股票价格和债券价格波动率的影响。结果表明 ,投资者的情绪波动对股票价格波动的影响要远大于对债券价格波动的影响 ;影响股票价格波动的情绪波动分别是主观贴现因子、跨期替代弹性和风险规避系数的波动。这些结果可以帮助我们理解股票价格的波动性和债券价格的平滑性。     

Uninsured idiosyncratic risk, liquidity constraints and aggregate fluctuations

Summary. I study the role played by uninsured idiosyncratic risk and liquidity constraints in the propagation of aggregate fluctuations. To this purpose, I compare the aggregate fluctuations of two model economies that differ in their insurance technologies only. In one of these model economies liquidity constrained households vary their holdings of a nominally denominated asset in order to buffer an uninsured idiosyncratic shock to their individual production opportunities. In the other economy every idiosyncratic component of risk can be costlessly insured. I find that the limited insurance technology implies fluctuations in output that are 20% larger, fluctuations in hours relative to output that are 9% larger, fluctuations in consumption relative to output that are 18% smaller, and a correlation of hours and productivity that is 15% smaller than those that obtain under the full insurance technology. Received: March 6, 1996; revised version August 15, 1996     

怎样解释中国经济波动： 基于BCA的分析

本文应用Business Cycle Accounting（BCA）方法,分析效率、劳动、投资和政府消费等扭曲性楔子对中国经济波动的影响。基于一个基本新古典增长模型,本文先从总量数据中估算出这些楔子的实现值,再分别将它们反馈到模型中以进行模拟实验;实验结果表明,只有效率楔子对解释中国经济波动是最重要的。这个发现为解释中国经济波动提供了一种新思路——让经济冲击或经济结构因素产生全要素生产率（TFP）波动,借此来引起其他相关变量的波动;这样建立的模型等价于带有效率楔子的基本增长模型,因此能够解释总量数据的大部分波动,而它们揭示的经济波动机制更有意义。经济周期政策应该更加关注TFP的变动,因为能够影响TFP的政策措施才能更有效地作用于经济波动。     

Time-Varying Risk, Interest Rates, and Exchange Rates in General Equilibrium

Under mild assumptions, the data indicate that fluctuations in nominal interest rate differentials across currencies are primarily fluctuations in time-varying risk. This finding is an immediate implication of the fact that exchange rates are roughly random walks. If most fluctuations in interest differentials are thought to be driven by monetary policy, then the data call for a theory which explains how changes in monetary policy change risk. Here, we propose such a theory based on a general equilibrium monetary model with an endogenous source of risk variation—a variable degree of asset market segmentation.     

On business cycle fluctuations in USA macroeconomic time series

This study employs eighteen USA macroeconomic time series variables to investigate possible existence of asymmetries in business cycle fluctuations in the series. Detection of asymmetric fluctuations in economic activity is important for policymakers since effective monetary policy relies on asymmetric business cycle fluctuations in all the series. The asymmetric deviations from the long-term growth trend in each of the series are modeled using regime switching models and artificial neural networks. The results based on nonlinear switching time series models reveal strong evidence of business cycle asymmetries in most of the series. The results based on in-sample approximations from artificial neural networks show statistically significant evidence of asymmetries in all the series. Similar results are obtained when jackknife out-of-sample approximations from artificial neural networks are used. Thus, the study results show statistically significant evidence of asymmetries in all the series which indicates that business cycle fluctuations in the series are asymmetric, thus alike. Therefore, the impact of monetary policy shocks on the output and the other macroeconomic variables can be anticipated using nonlinear models only. The results on asymmetric business cycle fluctuations in real GDP are in line with recent studies but in sharp contrast with Balke and Fomby (1994).     

Labor contracts,informational discrepancies and the role of monetary policy

This paper examines output stabilization and inflationary consequences of short-run monetary policy. The macroeconomic framework incorporates informational discrepancies between the monetary authority and economic agents who form long-term labor contracts. Economic agents are assumed to form rational expectations of the rate of inflation. One result of the analysis is that optimal monetary policy rules for stabilizing fluctuations in output and inflation are independent of the structure of the wage contracts and the degree of informational discrepancy. A second proposition shows that the monetary authority can actually make use of specific knowledge concerning the contract structure to reduce fluctuations in the rate of change in output. In particular, the monetary authority can reduce fluctuations in output below those occurring in a frictionless system by increasing fluctuations in the rate of inflation.     

Die Amplitude der österreichischen Konjunkturschwankungen im internationalen Vergleich

Summary Business cycles are considered to be milder in Austria than in other countries. This article tries to test if this view is correct. If it is correct it will investigate what are the factors dampening the amplitude of Austrian business cycles.It comes out in fact, that the fluctuations of global demand are considerably weaker in Austria than in almost all other industrialized countries. The amplitude of fluctuations of employment and prices is weaker as well but not that much so. Little evidence is found that Austria's better cyclical performance is due to superior discretionary policies. Rather the attempts to stabilize income and expectations in the long run may have contributed. Especially wages and disposable income stabilized private consumption, the evidence for a reduction of the amplitude of investment fluctuations via stabilizing entrepreneurs' expectations is much weaker. Strong evidence could be found that the fluctuations of the several components of demand compensate each other to a larger extent in Austria than elsewhere. The causes of the larger offset are not clear yet.An interesting sideproduct of this investigation is that the amplitudes of fluctuations and their patterns differ considerably from country to country. Policy can shape these patterns even if it is long-run policy and institutions rather than discretionary acts of fiscal and monetary policy. Especially price and quantity fluctuations are not alternatives. Good policy can dampen both at the same time.

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Der Autor dankt Univ.-Prof. Dr. Hans Seidel, Univ.-Doz. Dr. Karl Aiginger und den anonymen Gutachtern für wertvolle Anregungen und Verbesserungsvorschläge.     

中国改革历程中的产出和价格波动：货币所扮演的角色

中国经济正在其改革历程中经历着经济增长和通货膨胀的周期性波动。关于货币在这些波动中所起的作用，经济学家有着不同的观点。本文运用基于交易方程式的结构化VEC模型，对这些观点进行了探讨。我们发现，在长期，货币对产出和价格的变化做出适应性调整，而并非这些变化的原因。而在短期，价格变动要93因于那些对货币和价格有持久影响而对真实产出没有持久影响的冲击。这些冲击对多数的货币波动负责，并且强烈地影响产出。     

损失规避与经济波动的福利成本研究

目前经济波动的福利成本研究均建立在基于消费的效用函数基础上，而引入收入波动后我们发现：收入波动导致的福利成本才是更为重要的因素。本文定义的偏好具有损失规避的特点，在比较温和的参数设定下，考虑了收入波动后得到的福利成本指标A在1．4％--13．4％之间，比此前各种技术方法得到的A值提高了1—2个数量级。采用中国转型期以来的统计数据，消除短期波动的福利效果等同于将消费的长期增长率再提高约0．25个百分点，这表明如能进一步稳定经济的运行，仍会带来可观的福利提升。     

Relative price fluctuations in a two-sector model with imperfect competition

Counter-cyclical fluctuations in the price of investment in consumption units are often attributed to investment-specific technology shocks. This paper looks at an additional source for such fluctuations: sector-specific markup variations, the idea being that pro-cyclical competition and the higher variability of investment compared to consumption pushes down the relative price of investment during expansions. I find that such endogenous movements in sector-specific markups can account for up to about one quarter of the observed fluctuations in the price of investment.     

Fixed-term contracts as a source of labour demand fluctuations

Employment fluctuations are one of the central issues in the business cycle literature. The fluctuations depend crucially not only on the economic conditions but also on the labour market institutions. Since most previous studies have assumed indefinite-term contracts (ITC) implicitly, the implications of fixed-term contracts (FTC) on dynamic labour demand have been rather overlooked. This article investigates dynamic labour demand of a firm with FTC to show that the employment fluctuations under FTC can be totally different from those under ITC. In particular, a productivity shock that takes place at a future date generates the current fluctuations in employment under FTC, while it does not under ITC.     

Replacement,adoption and economic dynamics: lessons from a canonical creative destruction model

In this paper, we provide a first inspection into how structural technology adoption costs affect economic fluctuations. To this end, we choose a simple extension of a canonical creative destruction model. We analytically characterize the optimal replacement–adoption policies, and study numerically the induced dynamics. Our model predicts that the countries supporting the highest adoption costs are those which display the longest and sharpest business and employment fluctuations, and the lowest convergence speeds to their steady state equilibria. Moreover, as the position of the workers in the labor market weakens, the fluctuations are shown to get even sharper.     

中国改革历程中的产出和价格波动:货币所扮演的角色

中国经济正在其改革历程中经历着经济增长和通货膨胀的周期性波动.关于货币在这些波动中所起的作用,经济学家有着不同的观点.该文运用基于交易方程式的结构化 VEC 模型,对这些观点进行了探讨.我们发现,在长期,货币对产出和价格的变化做出适应性调整,而并非这些变化的原因.而在短期,价格变动要归因于那些对货币和价格有持久影响而对真实产出没有持久影响的冲击.这些冲击对多数的货币波动负责,并且强烈地影响产出.     

Keynesian Chaos

This paper shows how nonperiodic fluctuations can emerge in the standard fix price macroeconomic model when induced investment is strong enough. Specific functional forms are used to illustrate the phenomenon and to compute numerical evidence that nonperiodic fluctuations need not be rare.     

The role of agriculture in aggregate business cycles

There are substantial differences in business cycle fluctuations across countries. These differences are systematically related to the share of agriculture in the economy: Countries with a high share of employment in agriculture feature high fluctuations in aggregate output, low relative volatility of aggregate employment, and low correlation of aggregate output and employment. In addition, agriculture has certain distinctive features over the business cycle: Output and employment in agriculture are more volatile than and not positively correlated with output and employment in the rest of the economy and output and employment are less correlated in agriculture than in non-agriculture. Because of these features, agriculture may play a role in accounting for aggregate business cycles across countries. We calibrate an otherwise standard two-sector indivisible-labor business cycle model with agriculture and non-agriculture to aggregate and sectoral data for the United States. We find that an increase in the employment to population ratio in agriculture from 2 to 30 percent in our model increases fluctuations in aggregate output by almost 40 percent. This is about 2/3 of the difference in aggregate fluctuations between countries such as Turkey and the United States.     

中国信贷市场利率对经济波动的冲击效应研究

笔者基于VAR模型对我国信贷市场利率与经济波动的关系进行实证分析。研究结果表明:(1)信贷市场利率对投资、消费均处于负向冲击并有时滞,但对投资的影响更显著。投资、消费对信贷市场利率的影响非常有限。(2)投资波动对产出波动起主要作用;产出对投资波动和消费波动的影响程度有限;投资波动影响消费波动的程度远远大于后者对前者。基于这些分析结论,笔者提出若干政策建议。     

Optimal fiscal policy in sunspot‐driven oligopolistic economies

Economies with oligopolistic markets are prone to inefficient sunspot fluctuations triggered by autonomous changes in firms equilibrium conjectures. A well‐designed taxation‐subsidization scheme can eliminate these fluctuations by coordinating firms in each sector on a single equilibrium, left unaffected. The optimal taxation scheme must select the number of active firms that makes the best trade‐off (in terms of consumer welfare) between the markup and the scale inefficiency distortions. Implementing such stabilization policy leads to significant welfare gains, attributable to an “efficient stabilization effect,” typically ignored in usual computations of the welfare costs of fluctuations.     

The impact of coal price fluctuations on China’s economic output

Due to the important role of coal in China’s macroeconomic growth, the price of coal significantly influences its economic output. Employing a VAR model, a cointegration test and a state-space model of time-varying variables, this article analyses the influence of coal price fluctuations on the volume and structure of China’s economic output, including both the strength and the time delay of such influence. This article further explores the corresponding relationships between coal price fluctuations and variations in the effects of these fluctuations to analyse the asymmetric influence of coal price fluctuations on China’s macroeconomy. Coal price fluctuations exerted significant long-term positive effects and short-term negative effects on China’s output variables, with an average delay of 11 months; they had positive effects on investment and consumption over the long term and an increasingly negative effect on imports and exports. The average delays were 9 months for investment, 6.5 months for consumption and 10 months for imports and exports. There was an asymmetric correlation between coal price fluctuations and the time-varying elasticity of their impact on GDP. The results in this study are consistent with the actual operating circumstances of the Chinese economy.     

The Effect of Hysteresis on Fluctuations in Unemployment and Inflation when Inflation Expectations are Adaptive

The recent level of unemployment may affect the natural rate of unemployment. The implications of such an hysteresis effect for macroeconomic fluctuations is analyzed using a stochastic dynamic model. The greater the importance of an hysteresis effect, the more pronounced are fluctuations in unemployment and inflation. Complete hysteresis causes the economy to be unstable.     

FINANCIAL MARKET IMPERFECTIONS AND IRREGULAR GROWTH CYCLES

In this paper we analyze the generation of endogenous growth and irregular fluctuations in a simple New Keynesian model whose background assumptions are borrowed from a class of asymmetric information models popularized by Greenwald and Stiglitz. We extend the framework put forward by Greenwald and stiglitz taking explicitly into account technological progress as the engine of growth. We show how irregular endogenous fluctuations can arise around an endogenous trend: the traditional view of fluctuations as 'short run' phenomena must be abandoned in favour of models of fluctuating growth.