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。     

Intermediate Macroeconomics without the IS-LM Model

The IS-LM model is the primary model of economic fluctuations taught in intermediate-level undergraduate macroeconomics. Recent works by Taylor and Romer make a strong case for an alternative model, known as the aggregate demand-price adjustment (AD-PA) or the aggregate demand-inflation adjustment (AD-IA) model, as a better model of economic fluctuations. The author argues that the AD-PA model is superior to the IS-LM model for teaching about economic fluctuations in intermediate macroeconomics. He compares the perfomance of the two models in teaching about two important issues in current macroeconomics: the ineffectiveness of monetary policy in stimulating the 1990s Japanese economy and the rapid switch of the U.S. Federal Reserve from contractionary policy to expansionary policy in 2001.     

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。     

Business cycle fluctuations in Taiwan — A Bayesian DSGE analysis

This paper examines the Taiwanese economy in a small open economy DSGE model using Bayesian estimation. The model consists of two countries and 12 exogenous shocks with stochastic volatility to capture the fluctuations in the business cycle. The main results are: (1) shock innovations with stochastic volatility increase the model fit, (2) shocks originated from outside the country are important sources of fluctuations in the Taiwanese business cycle.     

Investment-specific shocks and real business cycles in emerging economies: Evidence from Brazil

This paper investigates the role of the RBC (Real Business Cycle) model with investment-specific technology shocks in explaining business cycle fluctuations in Brazil. I consider the role of transitory and permanent components of neutral and investment-specific technology shocks. I fit the model to the data using Bayesian techniques to show that the investment-specific shocks are important sources of fluctuations in the estimated model. In fact, in the context of the model, investment-specific shocks can account for remarkable percentages of fluctuations in consumption growth, GDP growth, investment growth and trade balance to GDP ratio. Furthermore, I present simulation evidence showing that the RBC model cannot account for some important features of the data.     

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     

Ergodic fluctuations in deterministic economic models

Nonperiodic business fluctuations are shown to exist with positive measure generically and to behave like stationary stochastic processes in the standard dynamic macro model. The implication is that so called ‘chaotic’ fluctuations are probable for random initial conditions in a large class of recursive economies.     

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.     

1980-2006年东亚经济波动的原因——基于面板VAR的分析

东亚经济波动及其协同性的存在已得到学术界的认同,文章通过构建面板向量自回归模型,检验了6种冲击对东亚经济波动的影响,并考察了宏观经济各变量在面时冲击时的动态反应,以及汇率和通货膨胀对经济波动的传导作用.研究表明,国内的供给冲击、汇率冲击,国外的利率冲击、需求冲击都会对东亚经济波动产生较大影响,汇率是外部冲击的重要传导渠道,而通胀是内部冲击的重要传导渠道.随着东亚经济一体化进程的推进和金融市场不断开放,东亚各经济体对外部需求变动和世界利率变动所产生的冲击应予以重视.     

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.     

Firm dynamics and markup variations: Implications for sunspot equilibria and endogenous economic fluctuations

This paper analyzes how the interaction between firms’ entry-and-exit decisions and variations in competition gives rise to self-fulfilling, expectation-driven fluctuations in aggregate economic activity and in measured total factor productivity (TFP). The analysis is based on a dynamic general equilibrium model in which net business formation is endogenously procyclical and leads to endogenous countercyclical variations in markups. This interaction leads to indeterminacy in which economic fluctuations occur as a result of self-fulfilling shifts in the beliefs of rational forward looking agents. When calibrated with empirically plausible parameter values and driven solely by self-fulfilling shocks to expectations, the model can quantitatively account for the main empirical regularities characterizing postwar U.S. business cycles and for 65% of the fluctuations in measured TFP.     

Underground economy and aggregate fluctuations

This paper explores the role of underground economic activities as an explanation of differences in registered aggregate fluctuations. In order to do so, we introduce an underground economy sector in an otherwise standard Real Business Cycle model and calibrate it to the USA economy. We find that, at low frequencies, Europe fluctuates more than the USA, while its participation rate is smaller. The existence of underground activities rationalizes the negative relationship between participation rates and fluctuations of registered output. Our model accounts for 44.3% of the differences in aggregate fluctuations between the USA and European economies. Finally, the model generates implied sizes of the underground economy of 3.2% and 7% of the American and European output, respectively, which are in the range of those found in the empirical literature.     

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。     

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。     

Structural financial instability and cyclical fluctuations

This paper introduces and discusses an heuristic model meant to clarify why and how economic instability may play a crucial role in a modern sophisticated monetary economy. In this model economic instability is specified in terms of structural instability rather than in the usual terms of dynamic instability. This different view of instability implies a different approach to the analysis of the dynamic behaviour of the economic system and of its structural changes. In particular, the qualitative changes in the economic behaviour of the economic system are seen not as purely exogenous as in the received view but as essentially endogenous. This approach is applied to the analysis of financial crises and of their impact on the fluctuations of a sophisticated monetary economy. The crucial variable, the degree of financial fragility of the economic units, is specified in terms of structural instability, and this implies that, beyond certain thresholds of its value, the qualitative characteristics of their dynamic behaviour change radically in such a way to produce cyclical, though fairly irregular, fluctuations. The interplay between these microeconomic fluctuations is sufficient to produce cyclical macroeconomic fluctuations whose characteristics and implications for policy are briefly examined.     

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.     

Financial fragility and economic fluctuations

This paper proposes a simple prototype model that describes the complex dynamics of a sophisticated monetary economy. The interaction between the current and intertemporal financial constraints on economic units brings about irregular fluctuations at both micro and macro levels. We use qualitative dynamic analysis and numerical simulations to investigate the interaction between financial fragility, modeled in terms of structural instability, and dynamically unstable financial fluctuations. The model, suggested recently by one of the authors, is here reformulated in more operational terms and extended in a number of new directions.     

ON THE SOURCES OF AGGREGATE FLUCTUATIONS IN EMERGING ECONOMIES

Recent research on macroeconomic fluctuations in emerging economies has advocated introducing a stochastic productivity trend or allowing for interest rate shocks and financial frictions. We estimate a model that encompasses these two approaches, shedding light on their relative merits and on how financial frictions affect the transmission of shocks. The model accounts for aggregate fluctuations by assigning a dominant role to financial frictions in amplifying conventional (temporary) productivity shocks, whereas trend shocks play a minor role. A link between spreads and expected future productivity emerges as essential for a reasonable approximation to the data.     

涉农行业投资增长波动的特征及影响因素

农业产业化的发展，需要涉农行业的带动和发展。本文利用HP滤波对9个涉农行业的投资增长趋势和波动进行了分解，对各行业投资增长波动特征进行了具体分析，并通过建立各行业投资增长的协整方程和反映各工业行业投资短期波动特征的误差修正模型，对各行业投资增长的长期影响因素及短期市场波动机制进行实证研究。实证分析结果表明，涉农行业的发展受税收政策和货币政策的影响而有所不同，国家应根据不同行业的情况采用不同的调控政策。