본 연구는 소비자 잉여, 소비자 자중손실 및 완전경쟁시장과의 비교 부문으로 이루어진 종합적인 분석 틀을 이용하여 1996∼2018년 간 추진된 제주-내륙 간 항공여객시장의 경제적 규제완화 정책에 대한 성과를 가늠하고, 허핀달지수(HHI)와 본 연구의 추정치 간 관계식을 이용한 향후 정책 활용 방안을 제시하는 것을 목적으로 하였다.
본 연구에서 구축한 실적 자료의 특성 및 실증 분석 결과를 요약하면 다음과 같다.
유임승객-km는 1996년 대비 2018년에 3배 이상 성장하였다. 특히, 저비용 항공사가 시장에 진입하기 전?후 연평균 증가율을 비교해보면 1996∼2006년(11년)은 2.2%이었지만, 이후 2007∼2018년(12년)은 8.1%로 뚜렷한 차이가 있다. 2018년 불변가격 기준 km당 운임도 연평균 증가율이 1996∼2006년(11년)에는 2.6%이었지만, 이후 2007∼2018년(12년)은 ?3.2%로 뚜렷한 차이가 있음을 확인할 수 있다. 이 기간 동안 운항횟수와 운항노선 수도 약 3배 정도 성장하였으며, 저비용 항공사가 시장에 진입하기 전?후 연평균 증가율도 뚜렷한 차이가 있음을 확인할 수 있다.
시장구조를 설명하는 대표적인 지수인 허핀달지수의 변화 양상을 살펴보면 다음과 같다. 1996년 0.606에서 2006년 0.560으로 이 기간 동안 연평균 증가율은 ?0.7%이다. 그러나 2007년에는 0.507, 2018년에는 0.169까지 감소하였으며, 이 기간 동안의 연평균 증가율은 ?8.8%에 달한다. 특히, 권역별 주요 노선은 2013년 이후 허핀달지수가 0.5 미만으로 하락하였고, 2018년 현재 0.20 내외 수준으로 분석 기간 동안 규제완화에 따른 저비용 항공사의 시장 진입으로 시장구조의 큰 변화가 발생한 것으로 분석되었다. 따라서 1996년부터 2018년 사이 정부가 추진한 일련의 규제완화 정책은 제주-내륙 간 항공여객시장을 다른 국가의 공항이나 세계 각국의 항공노선과 견주어 보더라도 상당히 낮은 허핀달지수에 이를 정도로 시장구조의 큰 변화를 이끌었다.
실증 분석 결과 1996년부터 2018년 사이 정부가 추진한 일련의 경제적 규제완화 정책은 제주-내륙 간 항공여객시장의 구조 변화를 이끌어 시장 경쟁을 촉진시키고, 항공사들의 시장 행위인 가격 전략의 변화를 불러 일으켜 소비자 잉여의 증가와 소비자 자중손실의 감소 등 소비자 관점에서 후생을 증가시키고, 자원의 비효율적인 배분을 개선시키는 등 시장성과를 달성한 것으로 분석되었다.
다음으로 본 연구는 정책 활용 방안으로서 실적 자료의 허핀달지수와 소비자 후생, 경제적 효율성 및 항공사의 수익성을 대표할 수 있는 추정치인 소비자 잉여(CS1～CS3), 추측행위탄력성, 매출액 대비 소비자 자중손실의 비율(추측행위탄력성 적용), 유임승객 1인당 마진(추측행위탄력성, 쿠르노 경쟁 가정)과의 관계를 분석하였다. 본 연구의 허핀달지수와 추정치 간 관계를 해석해 볼 때 제주-내륙 간 항공여객시장은 허핀달지수가 0.3～0.5인 구간에 위치하고 있을 때는 시장성과의 변화가 크지 않지만 허핀달지수가 0.30 이하에서는 그 증감에 따라 시장성과가 상대적으로 크게 변화하는 것으로 추정되었다. 따라서 정부는 허핀달지수가 0.3 이하에서 항공사들이 적정 수익을 창출할 수 있는 시장 집중도 수준에서 항공사 간 경쟁에 따라 시장구조가 형성될 수 있도록 이를 모니터링하고 항공 정책 방향을 설정할 필요가 있을 것으로 판단된다.
아울러 본 연구에서 제시한 이 방법론은 시장에서 관측되는 허핀달지수의 변화 양상을 이용하여 추정치의 변화를 추정한다는 점에서 적절한 정부 정책의 추진 시기나 방향을 설정하는 데 활용될 수 있고, 더 나아가 정부 정책의 성과를 예상할 수 있다는 점에서 국제선이나 노선 배분 심사 등 다양한 항공 정책 부문에서도 활용성이 높을 것으로 기대된다.

This study aims to analyze the outcomes of existing economic deregulation measures on the Jeju-mainland domestic air passenger market by using a comprehensive analytic framework considering consumer surplus (CS), consumer Deadweight loss (DWL), and a perfectly competitive market for comparison. It also intends to propose a method of applying the relationship between the Herfindahl-Hirschman index (HHI) and estimates derived in this study to policies. To this end, unbalanced panel data based on the air passenger market and socioeconomic indices in the temporal range between 1996 and 2018 were established. The properties of empirical data and results of empirical analysis obtained in this study are as follows.
The figure for revenue passenger-kilometers (RPK) increased more than three times from approximately 3.2 billion passengers-km in 1996 to approximately 10.4 billion passengers-km in 2018. In particular, the result of comparing the rates of annual average growth in RPK before and after the market entry of low-cost carriers (LCCs) indicates that the figure was 2.2% for 11 years between 1996 and 2006 and 8.1% for 12 years between 2007 and 2018, thus showing a marked difference.
The fare based on constant prices as of 2018 increased from 157 won/km (KRW) in 1996 to 232 won/km in 2002 after fare liberalization; it also exceeded 200 won/km in 2006. However, it fell below 200 won/km since 2009 and reached 137/km won in 2018. The result of comparing the rate of annual average growth in the fare indicates that the figure was 2.6% for 11 years between 1996 and 2006 and -3.2% for 12 years between 2007 and 2018, thereby showing a significant difference. Particularly, the fare was the highest in 2002, at which point LCCs had not yet entered the market after fare liberalization. It was relatively high in the years just before and after 2002 compared to other years. In other words, two full service carriers (FSCs) maintained high fares until LCCs entered the market in contrast with the intention of deregulation policies. Based on this result, it can be inferred that the fare liberalization policy of the Korean government, which aimed to improve market performance by adjusting market activities of airlines without a change in the market structure, was ineffective.
The number of flights over the years also changed drastically. The number of flights was approximately 56,000 times in 1996 and 65,000 times in 2006, thus presenting an annual average growth rate of 1.4%. After the market entry of LCCs, it was approximately 76,000 times in 2007 and 156,000 times in 2018, thereby presenting an annual average growth rate of 6.2%. The number of routes was 17 in 1996 and 2006 with a minor change observed between the years, whereas it significantly increased from 21 in 2007 to 49 in 2018.
The market structure can be examined through the application of the HHI which reflects the degree of market concentration. HHI of Jeju-mainland domestic all route was 0.606 in 1996 and 0.560 in 2006, thus showing an annual average growth rate of -0.7%. However, it decreased to 0.507 in 2007 and was as low as 0.169 in 2018, thus presenting an annual average growth rate of -8.8%. Specifically, HHI for routes such as Gimpo, Gimhae, Cheongju, Daegu, Gwangju, and Incheon, which serve as main regional routes, dropped below 0.5 after 2013 and reached approximately 0.20 as of 2018. Based on this result, it can be stated that a significant change in the market structure occurred due to the market entry of LCCs according to deregulation measures during the analysis period. Moreover, as confirmed in the result of low HHIs compared to that of other airport or routes over the world, it is confirmed that the series of deregulation measures implemented by the Korean government between 1996 and 2018 led to a substantial change in the structure of the Jeju-mainland domestic air passenger market.
As empirical analysis results, a decrease in market concentration triggered competition among the airlines. The result of examining a change in conjectural variation elasticity estimated in this study indicates that the figure was 0.3225 in 1996 and 0.2118 in 2006, thus showing an annual average growth rate of -3.7% during the period. Subsequently, it decreased to 0.0791 in 2018 with an annual average growth rate of ?7.5%. That is, as deregulation were implemented in the Jeju-mainland domestic air passenger market, which led to a decrease in market concentration and an increase in competition among airlines, the market power of airlines over fare also weakened. The result of the Lerner index applying conjectural variation elasticity decreased from 0.3970 in 1996 to 0.0791 in 2018. The value of the Lerner index applying Cournot competition decreased from 0.7465 in 1996 to 0.2079 in 2018. It was also found that the value of the margin per revenue passenger applying conjectural variation elasticity decreased from 22,918 won in 1996 to 5,106 won in 2018. Based on this result, it can be inferred that a change in the market structure affected by the market entry of LCCs led to competition among the airlines as well as a change in their market activities (i.e., pricing strategies).
In other words, an increase in the supply of airlines, market competition among the airlines, and a decrease in fare through the market entry of LCCs has led to the achievement of market performance such as an increase in CS and a decrease in DWL from the perspective of consumers.
More specifically, the result of conducting an empirical analysis on CS in the Jeju-mainland domestic air passenger market indicates that CS1, with both income effects and GDP increase effects excluded, increased from approximately 280 billion won in 1996 to 620 billion won in 2018. CS2, with income effects included and GDP increase effects excluded, increased from approximately 313.3 billion won in 1996 to approximately 690 billion won in 2018. CS3, with both income effects and GDP increase effects included, increased from 311.3 billion won in 1996 to 877.6 billion won in 2018. The rate of annual average growth of CS1 and CS2 was 2.6% for 11 years between 1996 and 2006, which then increased more than twice to 5.3% for 12 years between 2007 and 2018, thus showing a significant difference before and after the market entry of LCCs. The rate of annual average growth of CS3 with GDP increase effects included turned out to be 4.9% between 1996 and 2006 and 4.7% between 2007 and 2018. However, regarding the rate of annual average growth in GDP being 3.6% between 1996 and 2006 and 2.6% between 2007 and 2018, it is clear that there was a change in CS during the period before and after the market entry of LCCs.
On the contrary, the value of DWL applying conjectural variation elasticity consistently decreased from 32.4 billion won in 1996 to 5.5 billion won in 2018. The proportion of DWL compared to sales also decreased from 6.4% in 1996 to 0.4% in 2018. The value of DWL obtained with the assumption of Cournot competition applied also decreased from 114.4 billion won in 1996 to 25 billion won in 2018. Moreover, the proportion of DWL compared to sales decreased from 22.6% in 1996 to 1.8% in 2018. Although there is a difference between the results of the two empirical analyses, it can be inferred that DWL decreased according to the implementation of deregulation policies, in that the value shows a significant change before and after the market entry of LCCs.
As confirmed by the fact that the rate of runway utilization in Jeju International Airport was as low as 41% in 1996 and that it increased to 98% in 2018, the difference in demand between the real market and perfectly competitive market also showed a significant change. The result of comparing the demand based on the real market and perfectly competitive market is as follows. With conjectural variation elasticity applied, the demand in the real market in 1996 accounted for approximately 76% of that in the perfectly competitive market. However, the demand in the real market in 2018 accounted for 93% of that in the perfectly competitive market. With Cournot competition assumed, the demand in the real market in 1996 accounted for 62% of that in the perfectly competitive market. The demand in the real market in 2018 accounted for 86% of that in the perfectly competitive market.
Therefore, it can be concluded that the series of economic deregulation measures implemented by the Korean government between 1996 and 2018 led to the achievement of market performance such as acceleration of market competition among the airlines through a change in the structure of the Jeju-mainland domestic air passenger market, as well as an increase in CS and a decrease in DWL through a change in the market activities of airlines such as pricing strategies, which increased consumer welfare from the perspective of consumers, improving the inefficient allocation of resources.
The Korean government has executed policies to strengthen regulations on market entry, which are regarded as regulatory reform, beyond previous deregulation-focused policies since the enforcement decree of the aviation industry act was revised in 2018. Around this time, the examination of new licenses related to air transport businesses drew attention as a major issue in aviation policies.
This study analyzed HHI and its relations with CS (i.e., CS1 to CS3), conjectural variation elasticity, the proportion of DWL compared to sales based on conjectural variation elasticity applied, the margin per revenue passenger based on conjectural variation elasticity and Cournot competition assumed?which are estimates that can represent consumer welfare, economic efficiency, and profitability of airlines?to derive a method of applying the relations to policies. The analysis result of the relations between the HHI and estimates mentioned above indicates that a change in the performance of the Jeju-mainland domestic air passenger market is insignificant when the HHI ranges from 0.3 to 0.5. However, when the HHI is below 0.3, market performance significantly varies according to the value.
Therefore, the government should continuously monitor the market and set the direction of aviation policies to establish the market structure according to the competition between airlines within the level of market concentration, in which the value of HHI is below 0.3, and airlines can be guaranteed a proper amount of profits. Furthermore, the methodology proposed in this study can also be applied to determine an appropriate period or direction for the implementation of government policies, so that a change in the estimates can be investigated based on the HHI observed in the market. In addition, it can be broadly applied in various fields related to aviation policies, such as international flights and route assignment, as the outcomes of government policies can be estimated through this methodology.