I explore that South Korea’s major import fishery product markets-frozen hairtail, frozen mackerel, frozen pollock and frozen squid-are integrated by testing whether there is favorable evidence of the law of one price (LOP). Unlike previous studies on the LOP for fishery product markets, I assume non-zero import costs and include them in a trade model. To explore whether LOP holds for major import fishery product markets in South Korea with non-zero import costs, I utilize a non-linear time-series model, Smooth Transition Autoregressive (STAR) model with the sample periods from January in 2002 to December in 2019. I find that the behaviors of home-foreign price (i.e., import price) differentials of all four major import fishery products are non-linear depending on whether trade occurs and favorable evidence of LOP for each import market in South Korea. These findings indicate that each of South Korea’s major import fishery product markets is integrated. They imply that the supply of each major import fishery product-frozen hairtail, frozen pollock, frozen mackerel and frozen squid, and their prices are stable even if there is an economic shock on each market. When it comes to trade policy implications, the Korean trade policy including tariffs or quotas against their import countries for the four major import fishery products may not have influences on their price in the markets.

Although the main objective of Free Trade Agreements (FTA) is market integration among member countries, there are limited studies supporting this impact. Our study explores whether FTA has enhanced market integration between South Korea and its FTA partners, focusing on South Korea’s fishery product import market. We investigate two research questions concerning FTA impacts: first, whether trade costs declined when South Korea imported fishery products from its FTA partners after the FTA; second, if the speed of the convergence of South Korea-its FTA partners’price differential of imported fishery products on trade costs result to occur more quickly after the FTA. To determine these outcomes, we utilize a Threshold Autoregressive Model covering the sample periods from January 2002 to April 2017. Our findings demonstrate the effects of FTA on market integration are different among FTA partners. FTA has enhanced the market integration between South Korea and Norway, Vietnam, and Spain, respectively, but not for others. Therefore, we find positive evidence of FTA on fishery import market integration between South Korea and Norway, Vietnam and Spain, respectively.