BSS 모형을 이용한 자원평가기반의 생산효율성 추정 및 TAC 제도 효과 분석

Abstract

Korea is traditionally known as a country that consumes a lot of seafood, and a variety of seafood is produced due to its geographical characteristics. However, the amount of fisheries resources is decreasing significantly due to overfishing and illegal fishing. In addition, the catch that forms the basis for the supply of marine products was about 1,725,820tons in 1986, but remains at about 942,875tons as of 2021. Accordingly, the government is implementing various policies to restore fisheries resources. Therefore, this study aims to evaluate the fisheries resources of Korea's inshore and offshore fisheries and analyzes the effect of the Total Allowable Catch System implemented by the government. In addition, we analyze the production efficiency of offshore fisheries by estimating the Stochastic Frontier Analysis Production Function, and further propose ways to improve productivity by analyzing returns to scale and estimating marginal productivity. This study largely consists of three papers, and the specific contents are as follows. First, we estimate the amount of fisheries resources in 21 inshore and offshore fisheries. Second, we estimate the offshore fishing SFA production function and production efficiency and further analyze returns to scale and marginal productivity. Third, we analyze the effect of introducing the TAC system. The research results of the first paper are summarized as follows. First, the Gavaris general linear model was used to standardize the different fishing efforts of 21 inshore and offshore fisheries. As a result of estimating the bayesian state space model based on the standardization results, the amount of fishery resources was found to be approximately 2,981,135tons. This was found to be only 23.6% compared to 1987, and the status of fisheries resources as of 2021 was analyzed as “grossly overfished”. As a result of the second study, the production efficiency of Korea's offshore fisheries was analyzed. As a result of the analysis, it was found that there was a technical inefficiency of 53.8%, indicating that offshore fisheries production is being carried out quite inefficiently. Large purse seine, large otter trawl, and anchovy drag net had relatively high technical efficiency compared to other fisheries, and crew wages had a negative (-) marginal effect of technical inefficiency, and fuel costs had a positive (+) marginal effect. As a result of analyzing returns to scale for offshore fisheries, it was analyzed as Constant Returns to Scale throughout the entire period. While there were constant returns to scale from 1987 to 2003, the period from 2004 to 2021 shows diminishing returns to scale in all years except 2019. It was analyzed that the number of fishing boats has a significant impact as the main cause of diminishing returns to scale, and it was confirmed that a size reduction policy is necessary to improve the productivity of offshore fisheries that are experiencing diminishing returns to scale. As a result of the marginal productivity analysis of offshore fisheries, it was estimated that hiring one crew member increases the production of offshore fisheries by about 9.0245tons on average, and when the amount of fisheries resources increases by 1ton, production increases by 0.1013tons. On the other hand, when the number of fishing boats increases, production decreases by 21.1984tons. As a result of analyzing marginal productivity by industry, offshore fisheries were analyzed to be labor-intensive and resource-dependent at the same time. The marginal productivity of fishery resources was found to be positive (+) in all fisheries, and the marginal productivity of seafarers was estimated to be positive (+) in all fisheries, although there were differences in statistical significance by industry. On the other hand, the marginal productivity of fishing boats was estimated to be negative in 9 out of 13 fisheries. In particular, the marginal productivity of fishing boats in trawl fishing was found to be significantly lower than that of other fisheries. Therefore, it was confirmed that the number of fishing boats should be greatly reduced in order to solve the management difficulties of the trawl fishing industry(large purse Seine, large pair Bottom trawl, anchovy drag net), which is facing serious management difficulties. Overall, in order to improve the productivity of 13 offshore fisheries, the amount of fishery resources must be increased as a top priority. And it was found that production factors with positive (+) productivity should be increased, and production factors with negative (-) productivity should be reduced. The results of the third study are as follows. As a result of analyzing the effect of the TAC system, it was analyzed that the stocks of horse mackerel, red crab, blue crab, and sandfish species have increased since the introduction of the TAC system. In addition, these fish species satisfied the parallel trend assumption and were analyzed to have an effect of increasing resources due to the introduction of the TAC system. On the other hand, mackerel and squid showed a significant decrease in resource volume after the introduction of the TAC system. However, these fish species are known as transboundary resources and have the characteristic of sharing fisheries resources with neighboring countries. In particular, squid was confirmed in this study to be a result of decreased production due to illegal fishing in China rather than an effect of the TAC system. The policy implications based on the results of this study are as follows. First, in order to restore inshore and offshore fisheries resources, it is necessary to strengthen regulations on horse power along with fishing vessel reduction projects, and manage catch according to the TAC system. Second, the necessity and effectiveness of the fishing vessel reduction project being promoted by the government were statistically confirmed through analysis of returns to scale and marginal productivity. In particular, the marginal productivity of fishing boats in large-scale trawl fishing(large purse seine, large pair bottom trawl, anchovy drag net) is estimated to be significantly low. Therefore, it is judged that these fishing boats should be considered as a priority in reducing the number of fishing boats. Third, The effect of introducing the TAC system was partially confirmed. However, except for horse mackerel, the stocks of the remaining three fish species have recently been decreasing. Therefore, when allocating TAC in the future, it is judged that accurate TAC setting will be necessary through scientific stock assessment.