Testing for unit roots in time series models with non-stationary volatility

Many of the key macro-economic and financial variables in developed economies are characterized by permanent volatility shifts. It is known that conventional unit root tests are potentially unreliable in the presence of such behaviour, depending on a particular function (the variance profile) of the underlying volatility process. Somewhat surprisingly then, very little work has been undertaken to develop unit root tests which are robust to the presence of permanent volatility shifts. In this paper we fill this gap in the literature by proposing tests which are valid in the presence of a quite general class of permanent variance changes which includes single and multiple (abrupt and smooth-transition) volatility change processes as special cases. Our solution uses numerical methods to simulate the asymptotic null distribution of the statistics based on a consistent estimate of the variance profile which we also develop. The practitioner is not required to specify a parametric model for volatility. An empirical illustration using producer price inflation series from the Stock–Watson database is reported.     

社团法人持股规范问题探析

文章针对我国建筑业公司制企业社团法人持股现状,重点论述了这些企业如何规范社团法人持股,以适应国有企业新一轮改革的要求,促进企业持续健康发展。     

城市流动人口与城市化最低经济门槛作用机制之探讨

通过对比中外城市化进程发现 :城市流动人口与城市化最低经济门槛作用机制对于进城的农村人口顺利城市化起着至关重要的作用。这一机制的中心规律是就业支柱产业工资与城市物价的均衡 ,其正常运转的充要条件是产业增加值结构与产业就业结构同步转换 ;就业支柱产业处于世界产业体系中上游 ;人口规模适中 ;有较健全的社会保障体系和免费义务教育。在此基础上 ,经过量化处理 ,建立了城市流动人口与城市化最低经济门槛作用机制的简单模型     

我国服务业增加值的核算问题

本文集中讨论我国服务业增加值估算中存在的问题。由于历史原因和服务业本身的一些特点 ,我国现价服务业增加值被严重地低估了 ,服务业增长率计算也可能存在着偏差。对服务业增加值的以往研究均受到基础数据的限制而未能根本地解决这些问题。服务业统计核算的缺陷严重地阻碍着经济分析和经济决策。因此 ,改善我国服务业统计核算是当务之急。从长远的角度来说 ,服务业增加值核算的改善在很大程度上取决于统计调查的完善。但是 ,在现有的条件下 ,仍然有很大的改善余地。     

The micro-foundations of intertemporal price discrimination

Summary. This paper investigates the optimality of intertemporal price discrimination for a durable-good monopoly in a model where infinitely-lived households face an intertemporal budget constraint, and consume both durable goods and non-durable goods. We prove that the optimal price of the durable good is not constant, and may decrease or increase over time. Some households may choose to purchase the durable good at a later date, and pay lower or higher prices, since the gain in discounted utility of consuming more of the non-durable good more than compensates for the loss in utility from delaying the consumption of the durable good.Received: 12 March 2004, Revised: 7 January 2005, JEL Classification Numbers: D40, D42, D91.I would like to thank C.D. Aliprantis, the Editor, and an anonymous referee for their generous advice, and constructive comments and suggestions. I have also enjoyed discussions with John Quah on the subject. Research support from the Wharton-SMU Research Centre, Singapore Management University, is gratefully acknowledged.     

World Oil Depletion Models: Price effects compared with strategic or technological interventions

World oil depletion, including natural gas liquids, was modelled in the past by many authors. Recently, Guseo and Dalla Valle have introduced and Guidolin has applied a new approach following perturbed life-cycle diffusion models. Here we examine joint effects of economic and strategic or technological interventions using a Generalized Bass Model (GBM). Statistical analysis takes into account three different hierarchical levels: natural diffusion, long memory interventions and stochastic components. The main results confirm the statistical significance of historical 1970s shocks and highlight a strong long memory effect due to an increase in oil production after World War II. The estimated peak-date, 2007, and the 90% depletion time, 2019, are determined under an equilibrium intervention hypothesis.     

Competitive supply behavior when price information is fuzzy

The theory of fuzzy sets is applied to the output decisions of a price-taking firm facing imprecise information about expected future prices. Accepting risk resulting from the randomness of prices, the manager is interested in expected profits only. Since the set of possible expected-price vectors is fuzzy, a suitable defuzzification strategy is defined in analogy to the pessimism-optimism index proposed by L. Hurwicz. It depends on the manager's willingness to accept surprises resulting from a deviation of the true expected prices from the values that guided output decisions. Despite a linear cost function, well specified solutions to the optimization problem are possible without resorting to capacity constraints.     

我国旅游价格管理：现状、改革背景与政策分析

旅游业发展是一项复杂的系统工程，需要各相关行业和各项政策措施的配套协调。由于旅游价格的杠杆效应，如何应对入世给我国旅游业带来的挑战，改革并完善与国际接轨的旅游价格管理新体制是每一个旅游价格管理工作者应当思考的现实问题。     

会计信息质量与市场定价分析

本文以应计质量、盈余持续性、盈余可预测性、盈余平滑度作为会计信息质量的代理变量,通过研究会计信息不同纬度的质量与权益资本成本之间的关系,为投资者的市场定价及对信息质量的关注程度提供证据。研究结果表明,除盈余的持续性不显著外,其他各项质量与权益资本成本之间均呈负相关关系;在对权益资本成本的影响程度方面,无论是单独影响还是条件影响,应计质量影响程度最大,其次是可预测性。     

International Comparisons of Australia's Infrastructure Performance

International benchmarking has played a key role in the reform of Australia's infrastructure industries by promoting indirect or yardstick competition, in highlighting the need for further reform and building a consensus for implementing necessary changes. The international benchmarking of infrastructure performance by the Bureau of Industry Economics (BIE) between 1991 and 1996 did much to focus attention on the need for change. The BIE examined the performance of eight infrastructure industries relative to international best practice: electricity, rail freight, telecommunications, the waterfront, road freight, coastal shipping, aviation and gas supply. Performance comparisons concentrated on indicators of price, service quality, labour productivity and capital productivity. This paper reviews and summarises the performance comparisons the BIE undertook over the last three years of its infrastructure benchmarking program. The BIE international benchmarking program provides a useful role model for other countries wanting to seriously pursue reform of their infrastructure industries.