Monitoring recessions: A Bayesian sequential quickest detection method

Monitoring business cycles faces two potentially conflicting objectives: accuracy and timeliness. To strike a balance between these dual objectives, we propose a Bayesian sequential quickest detection method to identify turning points in real time with a sequential stopping time as a solution. Using four monthly indexes of real economic activity in the United States, we evaluated the method’s real-time ability to date the past five recessions. The proposed method identified similar turning-point dates as the National Bureau of Economic Research (NBER), with no false alarms, but on average, it dated peaks four months faster and troughs 10 months faster relative to the NBER announcement. The timeliness of our method is also notable compared to the dynamic factor Markov-switching model: the average lead time was about five months when dating peaks and two months when dating troughs.     

On exact D-optimal designs with 2 two-level factors and n autocorrelated observations

In this paper we consider the exact D-optimal designs for estimation of the unknown parameters in the two factors, each at only two-level, main effects model with autocorrelated errors. The vector of the n random errors in the observed responses is assumed to follow a first-order autoregressive model (AR(1)). The exact D-optimal designs seek the optimal combinations of the design levels as well as the optimal run orders, so that the determinant of the information matrix of BLUEs for the unknown parameters is maximized. Bora-Senta and Moyssiadis (1999) gave some conjectures about the exact D-optimal designs based on their experience of several exhaustive searches. In this paper their conjectures are partially proved to be true.Received: January 2003 / Accepted: October 2003Partially supported by the National Science Council of Taiwan, R.O.C. under grant NSC 91-2115-M-008-013.Supported in part by the National Science Council of Taiwan, R.O.C. under grant NSC 89-2118-M-110-003.     

Estimation methods for stochastic volatility models: a survey

Abstract.  Although stochastic volatility (SV) models have an intuitive appeal, their empirical application has been limited mainly due to difficulties involved in their estimation. The main problem is that the likelihood function is hard to evaluate. However, recently, several new estimation methods have been introduced and the literature on SV models has grown substantially. In this article, we review this literature. We describe the main estimators of the parameters and the underlying volatilities focusing on their advantages and limitations both from the theoretical and empirical point of view. We complete the survey with an application of the most important procedures to the S&P 500 stock price index.     

企业在同质产品市场的差异化战略行为——一个对我国反垄断立法的产业组织理论解释

我国在加入WTO后,一些重要的服务领域面临着全面对外开放。由于转换成本的存在,使得该领域中本来在购买前功能相近的同质商品或服务,在购买后成为异质的商品。企业因而拥有相对于消费者的事后垄断的权力。为此,企业有动机在初期采取战略行为吸引消费者。这既缓和了后续阶段的企业间竞争,也在整体上将该行业的产品价格维持较高水平。它可能会降低社会效率和消费者福利。文章通过分析企业间在同质商品市场竞争的市场效果和福利后果,为在我国该领域反垄断立法提供了理论解释。     

动态比较优势与中国目标产业选择实证分析

通过动态比较优势的理论模型，可揭示后进国家政策介入的必要性和有效性；采用独立随机增量过程马尔可夫链方法，可对中国制造业动态比较优势进行经验验证和预测。结果显示，弱比较劣势产业是目标产业。该些产业的优势状态保持不变或上移的概率高达80％以上，表明它们具有较大的潜在比较优势。     

Environmental tax policy in a model of growth cycles

Summary. The purpose of this paper is to consider environmental taxation which would control emissions of firms in a model of growth cycles. In the model presented below, the economy may experience two phases of growth and environmental quality: “the no-innovation growth regime” and “the innovation-led growth regime”. Aggregate capital and environmental quality remain constant in the no-innovation growth regime, while they perpetually increase in the innovation-led growth regime. The paper shows that the tax plays a key role in determining whether the economy stably converges to one of the two regimes or fluctuates permanently between them. It also shows that there is a critical level of the tax and that the economy obtains higher growth rates of capital and environmental quality by raising (or reducing) the tax if the initial tax is below (or above) the critical level. Received: April 2, 2001; revised version: March 21, 2002 RID="*" ID="*" This research reported here was conducted within the research project “Project on Intergenerational Equity” at Institute of Economic Research, Hitotsubashi University. I am deeply grateful to an anonymous referee for his or her insightful comments, which greatly improved the paper. I also thank Hiroshi Honda, Yasuo Maeda, Yuji Nakayama, and participants in workshops at Hitotsubashi University, Kyoto University, Nagoya University, Osaka University, University of Tsukuba, Yokohama National University, and University of Tokyo for their valuable comments and suggestions. Any remaining errors are mine.     

A Markov–switching vector equilibrium correction model of the UK labour market

There is a wide literature on the dynamic adjustment of employment and its relationship with the business cycle. In this paper we present a statistical model that offers a congruent representation of part of the UK labour market since the mid 1960s. We use a cointegrated vector autoregressive Markov-switching model in which some parameters change according to the phase of the business cycle. Output, employment, labour supply and real earnings are found to have a common cyclical component. The long run dynamics are characterized by one cointegrating vector relating unemployment to trend-adjusted real wages and output. Despite there having been many changes affecting this sector of the UK economy, the Markov-switching vector-equilibrium-correction model with three regimes (representing recession, normal growth, and high growth) provides a good characterization of the sample data, and performs well relative to alternative linear and non-linear models. The results of an impulse-response analysis highlight the dangers of using VARs when the constancy of the estimated coefficients has not been established, and demonstrate the advantages of generating regime dependent responses. First Version Received: December 2000/Final Version Received: August 2001     

Monetary and Fiscal Policy Interactions in the Euro Area

The problem of monetary and fiscal policy interactions is an important issue for the euro area, since the individual member states of the EMU are responsible for their fiscal policies but monetary policy is pursued by a single monetary authority, the ECB. This paper is concerned with empirical evidence on monetary and fiscal policy interactions in the euro area. We first explore fiscal regimes with a VAR model and find empirical evidence that a non-Ricardian fiscal policy has been pursued in both France and Germany. As an example, we then study how one member state of the EMU, namely, Italy, is responding to the common monetary policy with its fiscal policy and find that Italian fiscal policy seemed to be counteractive to the common monetary policy between 1979 and 1998. In order to study monetary and fiscal policy interactions in a more general way, we explore time-varying interactions by estimating a State-Space model with Markov-switching for some Euro-area countries. There appear to be some regime changes in monetary and fiscal policy interactions in France and Germany, but the interactions between the two policies are not strong. Moreover, the two policies have not been accommodative but counteractive to each other. Finally we explore forward-looking behavior in policy interactions and find that expectations do not seem to have played an important role in the policy designs.     

Managing the international commons: Resource use and pollution control

The simultaneous management, in an international context, of free-access renewable resources and transboundary pollution, is examined in a dynamic game framework. First-best outcomes under international cooperation are determined and compared to noncooperative outcomes when countries follow linear Markov strategies. An international policy consisting of taxes on emissions and harvesting, with international redistribution of tax receipts, is used to achieve the cooperative solution. In addition, side payments may be required to prevent free riding and thus make the international policy implementable.Earlier versions of this paper were presented at the International WorkshopEconomic Aspects of International Water Resources Utilization in the Mediterranean Basin, Fondazione ENI Enrico Mattei, Milan, October 1993, and the Fifth Annual Conference of EAERE, Dublin, June 1994. I would like to thank Peter Berck, Charles Kolstad, Mordechai Schechter, and two anonymous referees for their valuable comments.