A note on some properties of the ESTAR model

Some properties of ESTAR models are derived. We demonstrate that these models can exhibit chaotic dynamics and multiple equilibria. We show that a nonchaotic deterministic model with added noise can produce a time series that (falsely) appears to be chaotic.     

Can learnability save new-Keynesian models?

McCallum (2009) argues that “learnability” can save new-Keynesian models from indeterminacies. He claims the unique bounded equilibrium is learnable, and the explosive equilibria are not. However, he assumes that agents can directly observe the monetary policy shock. Reversing this assumption, I find the opposite: the bounded equilibrium is not learnable and the unbounded equilibria are learnable. More generally, I argue that a threat by the Fed to move to an “unlearnable” equilibrium for all but one value of inflation is a poor foundation for choosing the bounded equilibrium of a new-Keynesian model.     

Persistence of dollarization after price stabilization

Credit contracts in developing countries are often denominated in foreign currencies, even after many of these economies succeeded in controlling inflation. This paper proposes a new interpretation of this apparent puzzle based on the demand for insurance against real shocks: the fact that devaluations occur more frequently in adverse states of the world provides a motive for holding dollar assets. This approach implies a complementarity between the optimal monetary policy and the currency denomination of contracts. When a large proportion of liabilities is denominated in a foreign currency, the optimal exchange rate volatility is low, which reinforces the demand for dollar assets.     

Option grant backdating investigations and capital market discipline

Using a large sample of option granting firms, some of which were investigated for option grant backdating, we develop a predictive model for such investigations and examine how the capital market responded as the backdating scandal unfolded. Firms that were investigated experienced significant stock price declines from the beginning of the Wall Street Journal's Perfect Payday series through the end of 2006. Firms predicted to have backdating problems, but not the subject of publicly revealed investigations, experienced stock price performance during the same period that was remarkably similar to that of firms with publicly revealed investigations. In contrast, firms not predicted to have backdating problems experienced normal stock price performance. Our results suggest that capital markets disciplined companies with suspicious option grant histories, often prior to, and irrespective of, any public revelation of an investigation into the matter.     

略论我国司法解释存在的问题及完善

司法解释是我国法律解释中使用最广泛,且最主要的一种解释形式,它对于弥补法律规范本身存在的缺漏,以及保证法律的正确实施,具有重要的作用。然而,在我国法律实践中,司法解释还存在不少不容忽视的问题,对法律的准确、公正实施产生了消极影响。本文仅就司法解释中存在的检察解释的存在缺乏合理性、司法解释主体呈现"多元化"、"多级制"、司法解释"立法化"色彩浓厚这三个主要问题进行分析,并从规范司法解释主体、加强立法解释、强化全国人大常委会对司法解释的监督、强化法学家和公众意见对司法解释的引导和监督这几个方面提出完善的建议,以期对我国司法解释的发展有所裨益。     

我国审计市场类型分析及其启示

从市场中的“厂商”、“产品”、价格等要素来看,我国目前的审计市场显示为完全竞争市场。而根据福利经济学、信息经济学等对审计市场的分析,寡头垄断市场类型更适合理性的审计市场。结合国际上审计行业发展经验,本文认为,我国的审计市场类型将经历从完全竞争市场到寡头垄断市场的转变过程。在此基础上对市场类型转变过程中政府应给予的政策支持进行了探讨。     

Manipulation-proof equilibrium in atomless economies with commodity differentiation

Summary. In this paper, we introduce a perfect competition test which checks the incentives of arbitrarily small coalitions to behave strategically in endowments and preferences. We apply this coalitional incentive compatibility test to atomless economies with a continuum of differentiated commodities. We show that, under thickness conditions, economies with a finite number of types and economies whose set of agents' preferences is compact, pass this perfect competition test. Limiting results for replica economies are also presented. Received: July 25, 1997; revised version: December 5, 1998     

The set of sunspot equilibria in economies with incomplete financial markets: variable asset prices

Summary. I consider the set of equilibria of two-period economies with S extrinsic states of nature in the second period and I assets with linearly independent nominal payoffs. Asset prices are variable. If the number of agents is greater than (S-I), the payoff matrix is in general position and S 2I, the set of equilibrium allocations generically (in utility function space) contains a smooth manifold of dimension (S-1). Moreover, the map from states o f nature to equilibrium allocations (restricted to this manifold) is one-to-one at each equilibrium. Received: February 23, 1998; revised version: June 1, 2000     

A differentiable homotopy to compute Nash equilibria of n-person games

Summary. The literature on the computation of Nash equilibria in n-person games is dominated by simplicial methods. This paper is the first to introduce a globally convergent algorithm that fully exploits the differentiability present in the problem. It presents an everywhere differentiable homotopy to do the computations. The homotopy path can therefore be followed by several numerical techniques. Moreover, instead of computing some Nash equilibrium, the algorithm is constructed in such a way that it computes the Nash equilibrium selected by the tracing procedure of Harsanyi and Selten. As a by-product of our proofs it follows that for a generic game the tracing procedure defines a unique feasible path. The numerical performance of the algorithm is illustrated by means of several examples. Received: December 21, 1999; revised version: December 27, 2000     

马尔柯夫法在土壤质量动态评价中的应用

根据随机过程原理,构建了新的转移矩阵,建立了一个马尔柯夫链综合土壤质量评价模型;通过实例证明了模型的可靠性。