中国股市波动性研究——基于Shiller-Sentana-Wadhwani模型

股票市场的价格波动并非像传统金融学所说得那样围绕公司基本价值进行小幅震荡，常常表现出大幅波动的特征。本文采用基于garch模型作出的Shiller-Sentana-Wadhwani模型对中国股票市场成立十多年的股价波动进行实证研究，得出中国股票市场存在反馈交易且其程度随着股价波动的增大而提高、随着涨跌限制而加大的结论。     

Spatial agglomeration and endogenous growth

This paper constructs a dynamic general equilibrium model with spatial interactions in which a human capital externality is the centripetal force towards agglomeration. The resource cost of transportation is, on the other hand, the main centrifugal force, preventing a city from growing unboundedly. A central feature of our analysis is the dynamic interaction between (perpetual) economic growth and (bounded) city growth. We examine the socially optimal and the decentralized growth rates as well as city sizes. In the decentralized environment, individuals under-invest, whereas cities are under-populated. We show how public policies may enable a decentralized city to attain the socially optimal allocation.     

A Schumpeterian model of equilibrium unemployment and labor turnover

This paper constructs a general equilibrium model of equilibrium unemployment by combining an endogenous growth model with a variant of equilibrium search theory. The analysis offers two explanations for the causes of widening wage gap between skilled and less-skilled labor, and rising unemployment rate among the less skilled: technological change in the form of an increase in the size of innovations or skilled labor saving technological change in R&D activity. In addition, the model identifies two distinct effects of faster technological progress on the aggregate unemployment rate. First, it increases the rate of labor turnover and therefore increases the aggregate unemployment rate – the creative destruction effect. Second, it creates R&D jobs, which offer workers complete job security, and consequently reduces the aggregate unemployment rate – the resource reallocation effect.     

Convergences with Schumpeter: An essay Hirschman has yet to write

The paper explores the contributions of Joseph Schumpeter and Albert Hirschman to our understanding of the dynamics of modern democratic capitalist economies and suggests that much of their respective work displays intellectual overlap and complementarity. It is primarily focused upon the role of economic and political processes as forces of change and adjustment and the necessary degree of built-in inertia required to permit orderly rather than chaotic responses.     

Endogenous innovation under New Keynesian dynamic stochastic general equilibrium model

This paper constructs an endogenous growth model using the framework of New Keynesian dynamic stochastic general equilibrium models. We incorporate the Schumpeterian approach that generates seemingly sticky prices and reinterpret the Calvo mechanism from the perspective of Bertrand competition and successful entrepreneurs. Our results demonstrate that both positive productivity shocks and endogenous innovation have a negative effect on subsequent endogenous innovation. These self-destructive effects of endogenous innovation might account for the IT productivity paradox and productivity slowdown seen in advanced countries. Furthermore, it is shown that there are both neutral and non-neutral properties of monetary policy shocks. They are neutral in terms of the growth effect, but non-neutral in terms of the level effect. In particular, expansionist monetary policies are desirable to facilitate endogenous innovation.     

Endogenous fertility and modified Pareto-optimality

In a world of endogenous fertility, where the number of descendants is an integral part of the economic allocation, the traditional concept of Pareto-optimality cannot be applied any longer: the number of individuals to be present on earth may vary between any two allocations we wish to compare. Therefore, the concept needs to be modified in order to give new life to the discussion of economic efficiency. This work introduces a straightforward variation of the Pareto-principle and characterizes the optimality of economic allocations according to this concept. It is shown that some of the well-known traditional results on intertemporal optimality do no longer hold. In particular, lump-sum tax instruments (or the rearrangement of initial endowments) are no longer a sufficient tool to achieve efficiency. Received: March 2003, Accepted: September 2005 This work has greatly benefitted from comments by Oded Galor, Karl Shell, Vasco Santos and an excellent anonymous referee. Many thanks to the Editor of this Journal for providing an impeccable refereeing process. Support by the European Union via the Human Capital and Mobility Grant #ERBCHBICT941218 is gratefully acknowledged.     

Fluctuations in convex models of endogenous growth, II: Business cycle properties

Using ideas from the endogenous growth literature, we present a model of the endogenous determination of productivity growth based on individual worker decisions about human capital investment. We calibrate a version of the model to match long run growth facts from the US and study the business cycle properties of this model. This approach offers improvements along several dimensions over standard exogenous growth methodologies. Most importantly, our stochastic endogenous growth model generates much greater serial correlation in output growth and labor supply volatility relative to its real business cycle counterpart. We conclude that using the extra discipline of reproducing the trend productivity growth features of the data endogenously constitutes an important missing component from the real business cycle approach.     

Endogenous ranking and equilibrium Lorenz curve across (ex-ante) identical countries: A generalization

This paper proposes a symmetry-breaking model of trade with a finite number of identical countries and a continuum of tradeable consumption goods, which differ in their dependence on nontradeable intermediate inputs, “producer services”. Productivity of each country is endogenous due to country-specific external economies of scale in its service sector. It is shown that, in any stable equilibrium, the countries sort themselves into specializing in different sets of tradeable goods and that a strict ranking of countries in per capita income, TFP, the service sector share, and the capital–labor ratio emerge endogenously. Furthermore, the distribution of country shares, the Lorenz curve, is unique and analytically solvable in the limit, as the number of countries grows unbounded. Using this limit as an approximation allows us to study what determines the shape of distribution, perform various comparative statics and to evaluate the welfare effects of trade. In doing so, this paper extends the analysis of Matsuyama (Econometrica, 81:5 (September 2013), 2009–2031) for more general and flexible forms of scale economies. It turns out that the technique introduced in Matsuyama (Econometrica, 81:5 (September 2013), 2009–2031) is useful for the equilibrium characterization in this general case as well. Although some results of comparative statics and on welfare inevitably need to be modified, they change in ways that illuminate the underlying mechanism of symmetry-breaking.     

Spatial takeoff in the first industrial revolution

Using the framework of Desmet and Rossi-Hansberg (forthcoming), we present a model of spatial takeoff that is calibrated using spatially-disaggregated occupational data for England in c. 1710. The model predicts changes in the spatial distribution of agricultural and manufacturing employment which match data for c. 1817 and 1861. The model also matches a number of aggregate changes that characterise the first industrial revolution. Using counterfactual geographical distributions, we show that the initial concentration of productivity can matter for whether and when an industrial takeoff occurs. Subsidies to innovation in either sector can bring forward the date of takeoff while subsidies to the use of land by manufacturing firms can significantly delay a takeoff because it decreases spatial concentration of activity.     

中国货币政策对价格波动的影响

货币发行量对CPI变动具有负的影响。当前中国CPI居高不下,长期以来,中国一直存在着货币增速超过CPI增速、货币政策对资产泡沫的估算和调节能力有限、通胀指标难以确定等问题,针对这些情况,我们应综合运用货币政策工具,保持货币信贷合理投放,加大金融支持经济发展方式转变和经济结构调整的力度。完善人民币汇率形成机制,采取"外堵内疏"的策略,遏制国际投机资本冲击国内金融市场。