Convenient estimators for the panel probit model: Further results

Bertschek and Lechner (1998) propose several variants of a GMM estimator based on the period specific regression functions for the panel probit model. The analysis is motivated by the complexity of maximum likelihood estimation and the possibly excessive amount of time involved in maximum simulated likelihood estimation. But, for applications of the size considered in their study, full likelihood estimation is actually straightforward, and resort to GMM estimation for convenience is unnecessary. In this note, we reconsider maximum likelihood based estimation of their panel probit model then examine some extensions which can exploit the heterogeneity contained in their panel data set. Empirical results are obtained using the data set employed in the earlier study. Helpful comments and suggestions by Irene Bertschek and Michael Lechner are gratefully acknowledged. This paper has also benefited from comments by two anonymous referees and from seminar participants at the Center for Health Economics at the University of York. Any remaining errors are the responsibility of the author.     

A bioeconomic model for estimating the optimal level of deer and tag sales

This paper presents a dynamic model that determines the optimal number of deer hunting permit sales, subject to the objective of maximizing the discounted economic benefits stream from both the consumptive and nonconsumptive uses of deer. This bioeconomic model integrates economic benefits estimated using the dichotomous choice contingent valuation method with biological growth constraints on deer. Using a hunting zone in California as a case study, the model found that the optimal levels of buck hunting permits sold should change on a rotational basis over time and that the current practice of not selling doe hunting permits for that zone is non optimal.     

内地制药行业企业进入西藏市场的战略模式选择

内地制药行业企业进入西藏市场对其自身发展壮大和西藏居民健康状况的改善具有双重的意义，因此对进入的战略模式选择的研究是至关重要的。本文分析了内地制药行业企业进入西藏市场的必要性、可行性，在此基础上研究了进入市场的四种主要战略模式选择，阐述了不同战略模式的特征。希望本文的研究能够给我国制药企业的发展和西藏的医疗卫生进步作出贡献。     

商业模式创新途径探讨

如今商业环境变化迅速,持续地获得利润已经成为企业关注的焦点,商业模式给企业提供了参考的思维方法与实践框架。商业模式的组成要素包括:为谁,做什么,如何做,如何盈利四部分。其创新的途径主要有重新定义顾客,提供特别的产品/服务,改变提供产品/服务的路径,改变收入模式,改变对顾客的支持体系和发展独特的价值网络。企业有必要适时创新自身的商业模式,保证持续地盈利,获得竞争优势。     

A duration analysis of privatization in the telecom sector

The paper attempts to identify the telecom-sector performance indicators, relevant economic variables, and institutional characteristics of a country that effect the process of privatization of state-owned telecom enterprises. Using standard duration analysis of a panel data, we demonstrate that the privatization incentives are not only shaped by the mobility of financial capital in a country but are also influenced by the degree of competitiveness of private sector participation in policy-making process. The empirical results also reveal the significant impact of productive efficiency in telecom service provision on its course to privatization. We thank an anonymous referee for helpful comments and suggestions. We are solely responsible for all mistakes.     

临夏模式:形成、发展与转型

依赖于商贸经济和以皮毛加工为主导产业的临夏模式，未能使临夏实现经济起飞的原因是区际贸易的低水平均衡陷阱把其经济发展限制在了一个狭小的范围。因此，如何通过市场规模的扩展形成需求效应，是临夏这种欠发达民族开放地区实现区域工业化的基本途径。     

The Austrian current account deficit: Driven by twin deficits or by intertemporal expenditure allocation?

The evidence presented in the paper rejects the twin deficit hypothesis for the Austrian current account balance during the last two decades. The results are based on an estimate of a vector error correction model including quarterly data for the current account balance and potentially relevant variables driving its dynamics. We compute the variance decomposition of the current account's forecast error and its generalized impulse responses to shocks in the innovations of the system. The results in favor of intertemporal expenditure reallocation cannot be reproduced within a second analysis including the current account and a measure of net output, however. The estimated implicit current account balance, interpreted as the discounted expected change in future net output, does not follow the actual behaviour of the current account. First version received: June 1999/Final version received: March 2001     

循环经济认知误区的实证分析

随着传统经济增长模式危机的出现，世界各国纷纷提出并开始建立循环经济。循环经济作为一种崭新的社会经济发展模式，人们对其认识还存在种种误区，其中认为循环经济是一种最终实现“全新的封闭式的零排放的资源利用方式”、“可解决一切环境问题”的观点最为典型。那么，是否真的存在完美的全社会物质循环呢？实现这种循环的代价是什么？本文以物质循环为基本假设条件，应用扩张环境分析用投入产出模型对社会实现全循环的可能性进行了理论探讨．并以日本为例应用该模型对日本物质循环现状和在现有条件下实现全循环的可能性及其成本进行了实证分析，论证了在现有条件下实现全社会完美的物质循环的难点。     

Is Private R & D Spending Sensitive to Its Price? Empirical Evidence on Panel Data for Italy

In this paper empirical evidence is presented on theelasticity of private R & D spending on its price. Acensored panel-data regression model with random effectsis applied to a balanced panel of 726 Italian firms overthe 1992–1997 period. Implied estimates point out thatItalian firms' response to policy measures (including taxcredits), aimed at reducing the user cost of R & D capital,is likely to be substantial (1.50–1.77). Furthermore, wealso find that the elasticity of R & D spending is higherin recession (2.01) than in expansion (0.87).     

中英电信"双寡头垄断"模式比较研究

中国电信南北分拆以后,将在固定电话和移动电话两个业务领域形成新一轮"双寡头垄断"竞争格局.英国是率先实行"双寡头垄断"作为过度,最终走向电信全面开放竞争的典范.中国电信业在1994～1999年第一阶段改革中,曾试图仿效"英国模式",构建中国电信和中国联通的"双寡头垄断",最终以失败告终.在中国即将形成新一轮"双寡头垄断"竞争格局之时,我们有必要通过对英国电信改革的理论背景、具体实施过程、取得的成就的回顾,探求英国"双寡头垄断"成功的奥秘,并为中国新一轮电信重组所借鉴,提升中国的电信业国际竞争力,更好地应对WTO的挑战.