Tai-Yoo Kim

Dealing with zero response data from contingent valuation surveys: application of least absolute deviations estimator

Data on willingness-to-pay (WTP) collected from contingent valuation surveys are usuallycensoredat zero. Insuch cases, ordinary least squares estimationof the WTP equation produces inconsistent parameter estimates. The maximum likelihood estimation of the Tobit model, which is widely used in this case, is not robust to heteroscedasticity and non-normal error structure. A least absolute deviations estimator allows for the censored data structure and is robust to these problems. In addition, the technique is useful in the case of small amounts of data. It is applied to household survey data in which the contingent valuation question involved the benefit of greenhouse gases reduction policy in Korea.

Applying Multi-attribute Utility Theory to Decision Making in Environmental Planning: A Case Study of the Electric Utility in Korea

This paper applies the multi-attribute utility theory (MAUT) to obtaining value judgments concerning the significance of environmental impacts to achieve integration of environmental concerns at an early stage of planning, using the electric utility of Korea as a specific case study. An environmental multi-attribute index is constructed as a multi-attribute utility function, based on value judgments provided by a group of experts related to electric utility and a decision maker from Korea Electric Power Corporation (KEPCO). The societal values are derived from examining trade-offs between environmentalindex and money. The implications of the results for KEPCO are also discussed. We found that the work and results can provide valuable insights and decision opportunities for major decision making in environmental planning facing KEPCO.

A constructive approach to air-quality valuation in Korea

Abstract This paper uses a new constructive contingent valuation approach, based on the value-structuring capabilities of multi-attribute utility theory (MAUT) to help respondents construct and express environmental value judgments in monetary terms. The MAUT approach adopts a ‘decomposition’ procedure, which seems to be more in harmony with the constructive nature of human values and the coping strategies of respondents dealing with complexity. We provide an application of the approach in a survey of random population samples, where we seek valuation of specific damages due to air pollution in Seoul, Korea, a developing country where the economic valuation of environmental impacts remains scarce. A discussion of the results is also presented. The overall results show that although empirical evidence is sparse, there appears to be considerable scope for the use of the approach in environmental valuations.

BAYESIAN ESTIMATION OF MULTINOMIAL PROBIT MODELS OF WORK TRIP CHOICE

In this paper, we estimate a multinomial probit model of work trip mode choice in Seoul, Korea, using the Bayesian approach with Gibbs sampling. This method constructs a Markov chain Gibbs sampler that can be used to draw directly from the exact posterior distribution and perform finite sample likelihood inference. We estimate direct and cross-elasticities with respect to travel cost and the value of time. Our results show that travel demands are more sensitive to travel time than travel cost. The cross-elasticity results show that the bus has a greater substitute relation to the subway than the auto (and vice versa) and that an increase in the cost of an auto will increase the demand for bus transport more so than that of the subway.

Technological Progress versus Efficiency Gain in Manufacturing Sectors

This study decomposes the nonparametric Malmquist productivity index for 36 Korean manufacturing sectors into two components: technological change and technical efficiency change. The empirical results show that while each sector displays quite different growth patterns, productivity growth is dominated by technological change. Technological change is found to have a negative correlation with efficiency change. Secondary regression performed in this study identifies the relationship between productivity growth measures and several key policy variables, such as effective protection rate, market concentration, and so forth. The productivity estimates are compared with those of the conventional Tornqvist productivity index.

Digital identity: How users value the attributes of online identifiers

Abstract This paper examines online identifiers from an economic perspective. It uses conjoint analysis survey techniques to develop empirical data on how users value the attributes of online identifiers. It is concerned in particular with three issues: (1) the degree to which identified subjects value increasing the scope of an identifier, i.e., the ability to use a single identifier to access services offered by several organizations; (2) the degree to which users’ choice may be constrained by switching costs; and (3) the value individuals place on privacy and data security relative to other attributes such as cost or scope. The survey population was located in South Korea. The results indicate that e-mail addresses dominate the world of online identifiers for ordinary consumers; that consumers highly value increased scope (e.g., single sign-on capabilities) and the security of their private data; and that switching costs are high.

Modeling zero response data from willingness to pay surveys: A semi-parametric estimation

Abstract This paper models zero response data from willingness to pay surveys by employing parametric and semi-parametric estimation methods. The result of the specification test indicates the semi-parametric estimation outperforms the parametric estimation significantly.

International comparisons of productivity and its determinants in the natural gas industry

The objective of this paper was to evaluate the performance of the natural gas industry using an inter-country comparison of productivity level and its determinants. Three method- ologies: multilateral Tornqvist productivity analysis; managerial index system analysis; and ¨ non-parametric efficiency analysis, are employed to make a methodological cross-checking and to perform diversified analysis. From the empirical results, we identified the level and growth rate of productivity of individual firms. The results also indicated that the Korean gas industry has shown a relatively low level of productivity. From the results of managerial performance index analysis, we found that during the recent years of regulatory changes, the final price of gas has decreased dramatically while the productivity growth has not been enough to offset the effect of decreased output price, which has resulted in decreased profit. We also examine the extent of the allocative, scale, and managerial efficiency as source components of the overall efficiency based on the performance of best-practiced. With the results of this study, an effective policy measure could be established to improve the productivity and the overall managerial performance in the natural gas industry. Q 1999 Elsevier Science B.V. All rights reserved.

A practical approach for beginning the process of technology roadmapping

The study addresses the need for a robust yet practical technology roadmapping method that considers four major factors: input from consumers who use the technology; input from engineers who develop the technology; the technological gap between the roadmapped technology and competing technologies; and future changes in consumer preferences. The proposed method begins by using conjoint analysis of survey-derived consumer data to assess consumer requirements. Expert opinion is elicited regarding the relative importance of engineering characteristics, and any technological gaps are assessed. Quality function deployment is used to interconnect the results. The roadmapping method is applied to power line communications.

Profit, productivity, and price differential: an international performance comparison of the natural gas transportation industry

The objective of this paper is to evaluate the performance of natural gas transportation utilities, focusing on the three-key strategic performance measures of profit, productivity, and price differential. We propose a methodology that expresses the three performance measures in a unified single equation using the Edgeworth index. The proposed methodology is applied to an international comparison of the performance of 28 natural gas transportation utilities operating in eight countries in which the business environments differ greatly. The empirical results show the possible causes of performance differences and may shed some light on the direction of regulatory policy, especially for developing countries that have relatively short histories in the natural gas industry, such as Korea.