Seoul's CPTPP estimate trades 852 billion won a year of farm output for a 0.38-point GDP gain

The report's headline ratio, 7.9 times, sits at the top of the ministry's own range ^[8]. Divide the low-end manufacturing figure of 6.3 trillion won by the 852.3 billion won primary-sector loss and the multiple is about 7.4; only the 6.7 trillion won high end reaches 7.9 ^[1]. Neither version compares like with like. An official at an exporting company said the manufacturing number is net, combining output that falls and output that rises under wider tariff concessions, while the farm and fisheries number counts only domestic sales lost as imports displace local goods ^[9]. The manufacturing figure is also a production-inducement estimate that sweeps in upstream and downstream industries ^[4]. The report does not say whether the primary-sector figure was built the same way.

The time frames differ too. The 0.38-point GDP gain is measured ten years after entry ^[1], while both output figures are annual averages over 15 years ^[4][6]. Across that window the primary sector gives up about 12.8 trillion won of output, against 94.5 trillion to 100.5 trillion won of manufacturing inducement ^[2].

The loss is concentrated. Agriculture carries 710 billion won of the 852.3 billion, about 83%, with fisheries at 81.7 billion and forestry at 60.6 billion ^[7][3]. The gain is spread across manufacturers and their suppliers, and small and midsize firms take 1.1 trillion to 1.2 trillion won of it, roughly 18% ^[5][4].

The cash case for joining is in the export figures. Korean exports to CPTPP members were $164.8 billion last year, $41.9 billion more than went to the U.S. and $34 billion more than went to China ^[13][5]. "This is a market where we need to strengthen cooperation," a government official said ^[12]. Japan and Mexico are the only members without a Korean free trade agreement ^[14], and Mexico last year raised tariffs on steel, aluminum and auto parts by as much as 50% for countries without one ^[15]. Membership would lift access across the bloc without separate talks to upgrade each bilateral deal ^[17]. Seoul would be spending its negotiating time on one accession in place of a queue of bilateral upgrades. Deborah Elms, head of trade policy at the Hinrich Foundation, told a Federation of Korean Industries forum that Korea's most realistic option is to use existing structures such as the CPTPP as "selective partnerships" ^[20].

The numbers can still move in a few places. A like-for-like restatement would shift the 7.4-to-7.9 multiple: the exporter's point pushes it wider, and the supply-chain breadth of the inducement figure could push it narrower ^[9][4]. Japan is another variable. Past assessments warned that opening manufacturing to Japan would do heavy damage, and the current view in the report is that both sides gain in materials, parts and equipment ^[16]; a net manufacturing figure already carries that bet. Entry terms are a third. The pact admits members only by unanimous consent, and some warn the bar rises if China gets in first ^[19]. Tariff concessions across the bloc average 93.6% now and reach 98.8% at full implementation, according to the Korea International Trade Association ^[18].

I think the ministry's direction holds on its own figures. Even at 7.4 to 1, the gain covers the loss several times over, and the exporter official's line, "Looking purely at the macroeconomic effect, joining the CPTPP is the rational choice," is defensible on these numbers ^[10]. The counter-case is that an inducement total spread across supply chains will always look larger than a direct sales loss in one sector. The thesis fails if a final assessment, on one measurement basis and with Japanese competition inside it, brings the net manufacturing gain down toward the 852.3 billion won farm loss ^[6].