Bias and Efficiency of Uniform Bid Design in Contingent Valuation

While contingent valuation (CV) methods have experienced growing popularity for estimating the willingness to pay for nonmarket goods and services, optimal bid designs for CV that provide guidance in bid point placement often render themselves impractical by relying on pretest or prior information about the true distribution for willingness to pay. We investigate the use of a practical alternative to existing optimal or robust bid designs called the uniform design. Uniform design randomly draws bid points from a predetermined uniform distribution. Analytics and simulations show that the uniform design has higher low-bound of relative efficiency at 84 percent of D-optimum than a robust design. Simulations also demonstrate that uniform design outperforms other optimal designs when initial information about true parameters is poor and even outperforms robust designs when the true values of parameters are known.Research Methods/ Statistical Methods,

Temporal Insensitivity of Willingness to Pay: How do they evaluate in CVM?

In addition to scope and scale embedding effects, temporal insensitivity of willingness to pay, also known as temporal embedding effect, has been a well known anomaly in eliciting willingness to pay for environmental quality change, especially over time. Stevens et al. (1997) defines two types of temporal embedding effects: strong insensitivity and weak insensitivity to payment schedule. This paper proposes an alternative definition of the temporal insensitivity. Temporal insensitivity implies that a subject in the survey responds consistently to value elicitation questions regardless of payment schemes. The sequential test tests the temporal insensitivity using the oyster reef restoration programs in Chesapeake Bay. Test results show that willingness to pay for the program is insensitive to the payment scheme or to the length of benefit stream of the project. Discount rates imbedded in cost stream vary significantly among the combination of project lengths and payment schemes.Temporal insensitivity of willingness to pay, Temporal embedding effect, Implicit discount rate, Sequential test, Demand and Price Analysis,

REVISITING BID DESIGN ISSUES IN CONTINGENT VALUATION

A uniform bid design from a predetermined uniform distribution is proposed as a practical and robust alternative to existing optimal or naïve bid designs. Analytics and simulations show that the uniform design provides efficiency better than naïve designs under ideal conditions and outperforms optimal designs with poor initial information.Research Methods/ Statistical Methods,

Productivity Before and After Exports: The Case of Korean Food Processing Firms

In this article, we analyze the export decision of Korean manufacturing firms with emphasis on those in the food processing sector. A dynamic discrete choice model based on sunk (entry or exit) costs is specified for export behavior. Data for 1996-2002 on 1022 Korean firms, of which 95 are in the food processing sector, are assembled. A nonparametric measure of firm productivity is derived for use in the export-behavior (probit) model. Results show the significant effects of sunk costs on the export decision of Korean firms. A firm-size effect on export behavior is identified for food processing firms, unlike in the case of their manufacturing counterparts. We also find a firm-size effect on productivity in all manufacturing firms.Agribusiness,

Generalized Estimation Methods for Non-i.i.d. Binary Data: An Application to Dichotomous Choice Contingent Valuation

We challenge the assumption of i.i.d random utility across alternatives embedded in typical applications of logit models to dichotomous choice contingent valuation data. Using a Gumbel mixed distribution which nests a number of traditional models, we show that the logistic distribution is not a suitable distribution for contingent valuation analysis.Research Methods/ Statistical Methods,

The Impact of Trade Costs on Firm Entry, Exporting, and Survival in Korea

This study uses a unique firm-level dataset to examine how falling trade costs from 1993-2001 affected entry, exit, productivity, and exporting in the Korean manufacturing sector. We verify many of the predictions of recent heterogeneous-firm models of international trade. For example, falling trade costs reduced entry by new Korean firms, increased their probability of exit, and reduced the market share of surviving firms. We also find that small firms had a particularly high level of dynamism over the sample period. Small firms were more likely to enter and exit, and marginally more likely to gain market share, enter export markets for the first time, and improve their productivity.Employment, Exit, Exports, Firm deaths, Survival, Trade costs, Agribusiness, Industrial Organization, International Development, International Relations/Trade, Labor and Human Capital, Marketing, Production Economics, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies, F10, D24,

Trade and productivity effects on firm behavior : the case of Korean manufacturing

This dissertation’s three essays investigate trade and productivity effects on firm behavior based on new heterogeneous-firms trade models in the case of Korea. In the first essay, firms’ decision to export in the case of Korean manufacturing industries is examined, where the change in firms’ productivity before and after exports are analyzed. In particular, two common hypotheses of export decision - self-selection and learning-by-exporting- are tested using a dynamic model of firm export behavior and a Korean firm-level panel database. Evidence of self-selection is found in only three out of eight industries, but that of learning-by-exporting is limited. Sunk-cost or previous-export-experience effect on the predicted export probability is relatively larger than that of firms’ productivity and size. The second essay investigates the effect of trade cost changes on firms’ entry and exit in Korean manufacturing. Empirical support is found for new trade theories’ predictions on firm entry and exit, and the number of exporting firms, and changes in market share following trade-cost changes. However, Korean manufacturing appears to differ from some of the outcomes of the heterogeneous-firms theory, especially in the result that large firms are less likely to be a new exporter. Rather, smaller and less capital-intensive firms tended to enter the export market. In general, the results of this essay show that changing trade costs had important consequences for the structure of manufacturing activity in Korea. In the final essay, the differences in the scale economies of exporters and non-exporters in Korean manufacturing are investigated. Results from estimating a production function show that exporters face diseconomies of scale in four of five industries. A matching technique confirms the difference in returns to scale between exporters and non-exporters. The evidence that size and hence, scale economies may be less important for trade participation and gains from overseas market, bodes well for small or medium exporters. In summary, this dissertation has improved the understanding of the relationships among trade, productivity and firm behavior. The key determinant of firms’ export behavior in the Korean context appears to be previous experience in overseas markets. Not surprisingly, the Korean government has invested heavily in lowering their firms’ cost of accessing foreign markets. In industries where Korea has a comparative advantage, high productivity of firms appears to promote trade participation. However, productivity growth in other industries is low and falling, in some cases. A balanced approach to investments in productivity and export promotion would sustain and improve Korean manufacturing’s competitiveness in global markets

Bias and Efficiency of Uniform Bid Design in Contingent Valuation

While contingent valuation (CV) methods have experienced growing popularity for estimating the willingness to pay for nonmarket goods and services, optimal bid designs for CV that provide guidance in bid point placement often render themselves impractical by relying on pretest or prior information about the true distribution for willingness to pay. We investigate the use of a practical alternative to existing optimal or robust bid designs called the uniform design. Uniform design randomly draws bid points from a predetermined uniform distribution. Analytics and simulations show that the uniform design has higher low-bound of relative efficiency at 84 percent of D-optimum than a robust design. Simulations also demonstrate that uniform design outperforms other optimal designs when initial information about true parameters is poor and even outperforms robust designs when the true values of parameters are known

국소 영역 가열을 통한 능동 약물 전달이 가능하도록 젤라틴이 코팅된 슈크로스 기반의 생분해성 마이크로로봇

Microrobot, Magnetic actuation, Targeted drug delivery, Biodegradation, Con-trollable drug releaseNⅠ. INTRODUCTION 1 1.1 Microrobots for Minimally Invasive Cancer Therapy 1 1.1.1 Traditional methods of cancer therapy 1 1.1.2 Microrobots and actuation mechanisms 4 1.1.3 Magnetic actuation 9 1.1.4 Removal of microrobots after surgery 13 1.2 Research Trends 14 1.2.1 Drug delivery microrobots 14 1.2.2 Biocompatible and biodegradable microrobots 17 1.3 Objective of this Research 25 Ⅱ. MATERIALS AND FABRICATION 28 2.1 The SugarBot Materials 28 2.2 Fabrication of SugarBot 31 2.2.1 Sucrose composite fabrication 31 2.2.2 Sugar composite gelatin-coating process 33 Ⅲ. RESULTS AND DISCUSSION 35 3.1 Characterization of the Fabricated Gelatin-Coated SugarBot 35 3.1.1 Optimization of SugarBot fabrication 35 3.1.2 Biodegradability of SugarBot 39 3.1.3 Induction heating of SugarBot 42 3.1.4 Drug loading capacity of SugarBot 44 3.2 Magnetic Manipulation of SugarBot 45 3.3 Controlled Degradation of SugarBot 50 3.4 SugarBot In-Vitro Cell Viability Test 52 Ⅳ. CONCLUSION AND FUTURE WORK 59 4.1 Conclusions 59 4.2 Future Work 61 REFERENCES 63 요약문 73 Appendix 75MasterdCollectio

Generalized Estimation Methods for Non-i.i.d. Binary Data: An Application to Dichotomous Choice Contingent Valuation

We challenge the assumption of i.i.d random utility across alternatives embedded in typical applications of logit models to dichotomous choice contingent valuation data. Using a Gumbel mixed distribution which nests a number of traditional models, we show that the logistic distribution is not a suitable distribution for contingent valuation analysis