Technical innovation and 3.5 mobile phone generation: Lessons from Korea

In 1996, the Korean mobile communication market was the first in the world to commercialize the code division multiple access (CDMA). Since then, the voice-based mobile phone market has continued to grow and has now reached near saturation. Having recognized the potential of the mobile data service as a new source of profit, telecommunication operators are scrambling to evolve 3.5 generation (3.5G) technology in order to lead market competition. Recently, the Korean 3.5G mobile telecom market has faced stiff competition from CDMA-based EVDO Rev.A and global system for mobile telecommunications (GSM)-based high-speed downlink packet access (HSDPA). In addition, the world's first wireless LAN-based wireless broadband internet (WiBro) service was commercialized in June, 2006. This paper reviews the current status of the 3.5G technology and analyzes the service standardization strategies from the viewpoint of technological evolutions. This paper also suggests implications for Korea's specific circumstances where different mobile telecom technologies complement and compete with one another. Korea's experiences may serve as important lessons for other countries or operators who try to introduce the 3G and look beyond mobile telecom technologies.     

Delegation and polarization of platforms in political competition

Summary. We consider a model of political competition among two ideological parties who are uncertain about the distribution of voters. The distinguishing feature of the model is that parties can delegate electoral decisions to candidates by nomination. It is shown that if the credible platform commitments of the candidates is feasible, then at least one of the parties nominates in equilibrium to a candidate who has an ideology that is more radical than the delegating party's ideology. In a variety of circumstances, this, in turn, yields a polarization of equilibrium policy choices of the candidates. It is thus argued formally here that strategic nomination of the candidates may well be one of the major reasons behind the well documented observation that the platforms associated with the political parties in two-party democracies are often surprisingly polarized. Received: January 10, 2002; revised version: May 8, 2002 RID="*" ID="*" We thank Alberto Alesina, Levent Ko?kesen, Antonio Merlo, Ronny Razin, Vijay Krishna, Alessandro Lizzeri, and seminar participants at Alicante, Columbia, Copenhagen, and NYU for helpful comments. We also thank an anonymous referee for its useful suggestions. A good fraction of this research was conducted while Ok was a visitor in the Department of Economics at University of Alicante; he thanks for the kind hospitality of this institution. We gratefully acknowledge the financial support from the Spanish Ministry of Education through grant CICYT BEC2001-0535 (Faulí-Oller) and BEC2001-0980 (Ortu?o-Ortín). Correspondence to:I. Ortu?o-Ortin     

Segmenting Green Consumers in the United States: Implications for Green Marketing

The purpose of the current study was to segment U.S. consumers into four distinct clusters based on their beliefs and motives regarding pro-environmental consumer behavior. Using a nationally representative sample of U.S. adults from Experian Simmons (N = 22,348), this study revealed that: (a) there are four clusters of consumers in the United States with a unique set of beliefs and motives regarding consumer environmentalism; (b) the clusters have distinct demographic and media usage profiles; and (c) the groups have varying responses to the industry's initiatives to protect the environment. Implications of the research are discussed in light of developing message and media strategies for green marketing.     

中日农村医疗保险制度比较研究

纵向比较分析中日两国农村医疗保险制度的发展历程,从覆盖范围、筹资方式、补偿方式、资金收支情况等方面横向比较中日两国的农村医疗保险制度,探讨中日两国农村医疗保险制度的优缺点,为我国完善新型农村合作医疗制度提供相关建议。     

Free trade agreement and transport service trade

This study investigates the effects of free trade agreements (FTAs) on trade in transport services using OECD data from 2003 to 2006. Our analysis found that FTAs had a positive overall impact on transport services for multiple countries (i.e., 26 home and 56 partner countries). The resulting positive overall impact assures that, even with the challenges associated with different layers of services and the obstacles formed by generally low trade openness in the sector, the provisions in FTAs (e.g., national treatment and market access for goods and services) promote transport service trades. Our findings suggest that the provisions in FTAs encourage economic agents to increase engagement in transport services because of expanded openness of the physical movement of goods across international borders.     

Effects of rollover strategies and information stability on the performance measures in options markets: An examination of the KOSPI 200 index options market

One of the most widely used option valuation models among practitioners is the ad hoc Black–Scholes (AHBS) model. The main contribution of this study is methodological. We carefully consider two rollover strategies (nearest‐to‐next strategy and next‐to‐next) used in the AHBS model to investigate their effect on pricing errors. We suggest a new rollover strategy, next‐to‐next strategy, and demonstrate that our rollover strategy produces more consistent estimates between in‐sample market and model option prices. Probably even more important is that our new rollover strategy makes more accurate out‐of‐sample forecasts for 1‐day or 1‐week ahead prices. Prior literature has documented some anomalies associated with the use of AHBS model, for example, an overfitting problem. A secondary contribution is that our new rollover strategy does not suffer from this overfitting critique. Third, this study uses the mean square error for out‐of‐sample pricing and price changes to determine how the options investors are influenced by moneyness. The results indicate that underpricing (or overpricing) by the AHBS model for the near‐the‐money category is more likely to be maintained for the next several trading days but that such a phenomenon is disappeared for the deep out‐of‐the‐money category. Finally, we suggest the ratio of the number of option contracts to differences in strike prices available for trading between the current day and the previous day(s) as a good categorizing factor for options, such as moneyness. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark     

Dividend‐Rollover Effect and the Ad Hoc Black‐Scholes Model

One of the most widely used option‐valuation models among practitioners is the ad hoc Black‐Scholes (AHBS) model. The main contribution of this study is methodological. We carefully consider three dividend strategies (No dividend, Implied‐forward dividend, and Actual dividend) for the AHBS model to investigate their effect on pricing errors. We suggest a new dividend strategy, implied‐forward dividend, which incorporates expectational information on dividends embedded in option prices. We demonstrate that our implied‐forward dividend strategy produces more consistent estimates between in‐sample market and model option prices. More importantly our new implied‐forward dividend strategy makes more accurate out‐of‐sample forecasts for one‐day or one‐week ahead prices. Second, we document that both a “Return‐volatility” Smile and a “Return‐pricing Error” Smile exist. From these return characteristics, we make two conclusions: (1) the return dependency of implied volatility is an important explanatory variable and should be controlled to reduce the pricing error of an AHBS model, and (2) it is important for the hedging horizon to be based on return size, that is, the larger the contemporaneous return, the more frequent an option issuer must rebalance the option's hedge. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark 32:742‐772, 2012     

Die Außenwirtschaft der UdSSR in der zeit von perestrojka

The study of divided government is one of important fields in public choice theory. American voters split their ballots as if intent on preserving divided party control. The U.S. House of Representatives has consistently been Democratic for much of the twentieth century. As indicated by Sprague, it is theoretically true that a number of significant consequences for partisan control of a legislature are entailed by the unequal distribution of seat safety under conditions of high levels of institutionalization. The problem is how to measure the institutionalization of partisan seat safety in a time‐series. The model proposed by Sprague is somewhat awkward and complicated in measuring it. This paper provides a more plausible model and tests empirical data.     

The measurement of income mobility: A partial ordering approach

Summary. Given a set of longitudinal data pertaining to two populations, a question of interest is the following: Which population has experienced a greater extent of income mobility? The aim of the present paper is to develop a systematic way of answering this question. We first put forth four axioms for income movement-mobility indices, and show that a familiar class of measures is characterized by these axioms. An unambiguous (partial) ordering is then defined as the intersection of the (complete) orderings induced by the mobility measures which belong to the characterized class; a transformation of income distributions is “more mobile” than another if, and only if, the former is ranked higher than the latter for all mobility measures which satisfy our axioms. Unfortunately, our mobility ordering depends on a parameter, and therefore, it is not readily apparent how one can apply it to panel data directly. In the second part of the paper, therefore, we derive several sets of parameter-free necessary and sufficient conditions which allow one to use the proposed mobility ordering in making unambiguous income mobility comparisons in practice. Received: July 12, 1995; revised version: May 13, 1997     

Fuzzy measurement of income inequality: Some possibility results on the fuzzification of the lorenz ordering

Summary This paper starts from the premise that the concept of income inequality is ill-defined, and hence, it studies the measurement of income inequality from a fuzzy set theoretical point of view. It is argued that the standard (fuzzy) transitivity concepts are not compatible with fuzzy inequality orderings which respect Lorenz ordering. For instance, we show that there does not exist a max-min transitive fuzzy relation on a given income distribution space which ranks distributions unambiguously according to the Lorenz criterion whenever they can actually be ranked by it. Weakening the imposed transitivity concept, it is possible to escape from the noted impossibility theorems. We introduce some alternative transitivity concepts for fuzzy relations, and subsequently, construct a class of fuzzy orderings which preserve Lorenz ordering and satisfy these alternative transitivities. It is also shown that fuzzy measurement can be used to construct confidence intervals for the crisp conclusions of inequality indices.I wish to thank Ashish Banerjee, Kaushik Basu, Larry Blume, Gary Fields, Semih Koray, Tapan Mitra, Antony Shorrocks, Sinan Unur and two anonymous referees of this journal for insighthul comments and suggestions. I am also grateful to the participants of the 1993 Midwest Mathematical Economics Conference held in University of Wisconsin at Madison and the 2nd International Meeting of the Society for Social Choice and Welfare held in University of Rochester.