The impact of mobile financial services’ usage on microfinance delinquency

This paper studies the impact of Mobile Financial Systems’ usage on microcredit delinquency ratios in Tunisia by using either a two-part model or matching econometric procedures. Our large dataset contains all of the administrative registers that belong to the six branches of Enda, the incumbent Institution leader in Tunisia. We find a significant reduction of 4.92 days of late repayment for an average user of MFS in an environment where 15% of loans have been paid late at least once. We foresee a tremendous opportunity to improve the MFIs’ repayment ratios and, consequently, provide microcredit customers with more financing for income generating activities.     

Conjoint and WTP analyses of future mobile phones for digital convergence

Digital convergence for mobile phones is a hot issue. This study considers future development of mobile phones with a view toward consumers' usage and the amount they are willing to pay. In order to select preferable convergence technology, we utilize convergence concepts such as absorption, blending, and combination. The result of conjoint analysis shows that a preference for convergence technology will involve computing, media, navigation, and imaging. However, only the computing attribute increases consumers' willingness to pay. Our study results contribute to product planning and commercialization of innovative mobile phones.     

Australian Residential Telecommunications Consumption and Substitution Patterns

Better telecommunications pricing decisions are able to be made when more complete information concerning relationships among services is available. This study analyses residential fixed-line and mobile telephony, and Internet access and usage demands in an encompassing framework. The discrete-continuous framework allows for service interaction within and between service portfolios. Model estimation is based on the examination of data collected from a country-wide survey of Australian households. In particular, observed service portfolios (household consumption patterns at prevailing access prices and estimated average service usage prices), income and demographic characteristic data are collected. These data also allow the modelling to potentially identify market segments based on income and other household characteristics.JEL Classifications: D12, L11, L69     

Optimal Time-of-use Access Charges

This paper examines the setting of optimal time-of-use access charges in a deregulated network industry environment. Firms, which may include the incumbent, compete in the final retail market. The regulator sets an access fee for use of the essential facility, allowing the incumbent to recover fixed costs. If the retail market is perfectly competitive the optimal access charge varies with time-of-use according to the Ramsey–Boiteux elasticity rule. However, with downstream market power the regulator needs to correct retail price distortion, as well as recover fixed costs efficiently. As a result, the regulators initial impulse to set higher access charges during peak periods may be reinforced, moderated or even reversed — and optimal access charges diverge from a Ramsey–Boiteux pattern.I would like to thank John Panzar and Julian Wright for helpful comments. The helpful and detailed remarks of an anonymous referee have greatly improved this paper and are gratefully acknowledged.     

移动AdHoc网络中的TCP改进技术

近年来，有关移动Ad Hoc网络的关键技术研究已经取得了很大的进展，如何有效地提高其网络性能仍然是目前研究的热点问题。本文结合这种网络拓扑动态变化、路由易发生改变的特点，分析了传统TCP协议在应用上遇到的挑战，并从两个途径研究了针对TCP技术的各种改进方案，同时提出了今后可能的研究方向。     

采用软件无线电技术的多模接收机结构

对移动通信中采用多模手机的必要性及各种不同的软件无线电结构进行了描述,提出了采用软件无线电技术低中频原则,可接收多种移动通信体制信号的多模接收机结构,并对该结构的优缺点及决定资源需求的各种因素进行了讨论。     

WCDMA网络移动台定位技术分析与探讨

介绍了具有移动台定位功能的WCDMA网络结构，分析了网络中采用的3种基本定位技术的特点及实施方法，对定位技术中可供研究的课题进行了探讨，提出了主要研究方向。     

Privatizing Monopolies in Developing Countries: The Real Effects of Exclusivity Periods in Telecommunications

Many developing countries have given newly privatized incumbent network utilities, especially telecommunications, exclusive rights to serve particular markets. Research to date has explored privatization, competition, and to a lesser extent, regulation. We know little, however, about the effects of the privatization transactions themselves and, in particular, how these exclusivity periods matter. I use original data to investigate this approach to privatization. I find that exclusivity periods are associated with significant increases in the firms sale price. Exclusivity periods are also, however, correlated with a significant decrease in the incumbents investment in the telecommunications network, payphones, mobile telephone penetration, and international calling.JEL Classification: L1, L5, L96, O12I am grateful for the thoughtful comments and suggestions of Luke Haggarty, Tom Hazlett, Phil Keefer, Roger Noll, Russ Pittman, Greg Rosston, David Sappington, Mary Shirley, Lixin Colin Xu, and two anonymous referees. I thank Troy Kravitz for research assistance. I am solely responsible for all mistakes.     

A generalized additive Tobit model

This paper proposes a semi-parametric approach to estimation in Tobit models. A generalized additive Tobit model of residential local long distance (intra-LATA) telephone demand is estimated on a cross-section of residential telephone consumers across twenty-eight states. While past studies of telecommunications demand have used fully parametric models, the model presented here is non-parametric in two dimensions: first no distributional assumption is made for the error distribution, and second, the demand equation is non-parametric with respect to price. We find that the elasticity of demand is substantially lower (in absolute value) that found in previous studies for a 40% cut in tariffs. First version received: July 2000/Final version received: March 2001 RID="*" ID="*"  I thank the referee and Associate Editor for suggestions which improved the paper. The views expressed here are of the author and not Analysis Group | Economics.     

我国新一代移动通信体制问题及若干对策

发展第三代（3G）移动通信系统已经在全于范围内达成了共识。本文针对中国新一代移动通信体制问题进行了相关讨论，并就若干发展战略进行了探讨。