에너지경제연구 Korean Energy Economic Review Volume 12, Number 1, March 2013 : pp. 125~158 알뜰주유소전환으로인한자영주유소의 휘발유가격인하효과분석 125
126
127
128
129
130
131
132
비알뜰주유소 정책시행후 비알뜰주유소 정책시행전 시행후 시행전 알뜰주유소 정책시행후 알뜰주유소 정책시행전 시행후 시행전 알뜰주유소 정책시행후 알뜰주유소 정책시행전 비알뜰주유소 정책시행후 비알뜰주유소 정책시행전 133
[ 그림 Ⅱ-1] 이중차분모형에서의정책효과 5) 134
135
[ 그림 Ⅱ-2] 실험군과대조군휘발유가격추이 136
137
138
[ 그림 Ⅱ-2] 비모수이중차분모형의인과관계효과 139
[ 그림 Ⅱ-3] 비모수이중차분모형의인과관계효과 140
141
142
143
< 표 Ⅲ-1> 실험군 / 대조군여부에따른평균휘발유가격 < 표 Ⅲ-2> 전환월별알뜰주유소개수와평균휘발유가격 144
< 표 Ⅲ-3> 지역별주유소수와평균휘발유가격 145
< 표 Ⅲ-4> 주유소상표별주유소수와평균휘발유가격 ~ 146
< 표 Ⅳ-1> 이중차분모형의추정결과 : 대조군 1 < 표 Ⅳ-2> 이중차분모형의추정결과 : 대조군 2 < 표 Ⅳ-3> 이중차분모형의추정결과 : 대조군 3 147
~ 148
< 표 Ⅳ-4> 이중차분모형 3 의추정결과 ( 계속 ) 149
< 표 Ⅳ-5> 비모수이중차분모형의추정결과 ~ 150
151
[ 그림 Ⅳ-1] 비모수이중차분모형을통한추정누적분포 : 대조군 1 [ 그림 Ⅳ-2] 비모수이중차분모형을통한추정누적분포 : 대조군 2 152
[ 그림 Ⅳ-3] 비모수이중차분모형을통한추정누적분포 : 대조군 3 153
154
접수일 (2013 년 2 월 26 일 ), 수정일 (2013 년 3 월 25 일 ), 게재확정일 (2013 년 3 월 30 일 ) 155
, 2010.,., 2009.,., 2012.,. Adamowicz, W. Louviere, J. and Williams, M. 1994. Combining Revealed and Stated Preference Methods for Valuing Environmental Amenities. Journal of Environmental Economics and Management 26 : pp271-292. Angrist, Joshua D. and Jörn-Steffen Pischke, 2009. Mostly Harmless Econometrics: An Empiricist s Companion, Princeton. Athey, Susan and Guido W. Imbens, 2006. Identification and Inference in Nonlinear Difference-in-Differences Models, Econometrica, 74, 431-497. Eckert, Andrew and Douglas, S., West, 2005. Price Uniformity and Competition in a Retail Gasoline Market, Journal of Economic Behavior and Organization, 56, 219-237. Hastings, Justin S., 2004. Vertical Relationships and Competition in Retail Gasoline Markets: Empirical Evidence from Contract Changes in Southern California, American Economic Review, 94, 317-328., 2010. Vertical Relationships and Competition in Retail Gasoline Markets: Empirical Evidence from Contract Changes in Southern California: Reply, American Economic Review, 100, 1277-1279. Netz, Janet S., and Beck A. Taylor, 2002. Maximum or Minimum Differentiation? Location Patterns of Retail Outlets, The Review of Economics and Statistics, 84, 162-175. Pennerstorfer, Dieter, 2008. Spatial Price Competition in Retail Gasoline Market: 156
Evidence from Austria, Annals of Regional Science, 43, 133-158. Pinske, Joris, Margaret E. Slade and Craig Brett, 2002. Spatial Price Competition: A Semiparametric Approach, Econometrica, 70, 1111-1153. Taylor, Christopher T., Nicholas M. Kreisle, and Paul R. Zimmerman, 2010. Vertical relationships and competition in retail gasoline markets: Empirical evidence from contract changes in Southern California: Comment. American Economic Review, 100, 12691276. Slade, Margaret E., 1986. Conjectures, Firm Characteristics, and Market Structure, International Journal of Industrial Organization, 4, 347-369. 157
ABSTRACT Facing record-high level of oil prices and increasing volatility in gasoline market, Korean government has introduced a new type of discount gas stations so-called Thrifty gas stations. By diversifying supply channels and consumer options, the Korean government aimed to boost the competitions among gas stations thus mitigating the burden of households utility bills. The purpose of this study is to analyse the impact of the introduction of thrifty stations on gasoline prices. This is more subtle task than one might expect since the gas stations which chose to convert into thrifty stations may have been selling their products at lower prices than average gas stations even before the conversion. Thus simple comparisons between thrifty stations and the others may not provide us an appropriate ex pose impact assessment. In order to minimize such problems and control the group-specific effects over time, here we use parametric and non-parametric difference-in-differences approaches. Our estimation results indicate that the price of a gas station decreases approximately by 20 KRW after its conversion into a thrifty station and a station near (within 3km radius) to a thrifty station sells its product at a price 3~7 KRW lower on average. Key Words : Gasoline price, Thrifty stations, Difference-in-differences, JEL Codes : L11, L98, L99 Non-parametric difference-in-differences 158