近年來，美國等主要市場透過國安措施（如 Section 232）及其他貿易政策工具提高進口關稅，使跨國製造商在「離岸生產出口」與「在地設廠生產」之間面臨更明顯的決策權衡。離岸生產通常具備較低生產成本，但產品出口至目標市場時需承擔關稅負擔；相對地，在地生產雖需投入固定成本與長期產能投資，卻可能獲得政策端與市場端之回饋，例如關稅減免、關稅豁免、消費者溢價或需求擴張。尤其當政策採行「達到在地化門檻後始給予優惠」之機制時，企業決策不再僅是平滑調整生產比例，而可能出現為跨越門檻而增加在地投資，或將在地生產比例維持在剛好達標水準之跳躍式行為。 基於此，本研究以跨國製造商為決策主體，建構一個結合關稅、在地化門檻與消費者溢價之兩階段決策模型，並利用逆向歸納法進行分析，探討在「關稅與在地化要求並存」且「達標後同時享有稅率下降與市場溢價」的制度環境下，企業最適之在地產能投資與境內外生產數量決策。本文假設企業於單一目標市場銷售單一產品，並可透過在地生產與離岸生產兩種方式滿足市場需求。其中，離岸生產並出口至目標市場之產品需負擔從價關稅；在地化程度則以在地生產數量占總生產數量之比例衡量。當在地化比例未達門檻時，離岸生產適用較高關稅；一旦達標，則可適用較低稅率，甚至享有完全豁免。此外，企業達標後亦可因在地化認證、品牌信任或消費偏好而獲得額外價格溢價，進一步改變最適生產與投資決策。;In recent years， major economies such as the United States have raised import tariffs through national security measures and other trade policy instruments， creating a more pronounced trade-off between offshore production for export and local production for multinational manufacturers. While offshore production generally offers lower production costs， products exported to the target market are subject to tariffs. In contrast， local production requires fixed costs and long-term capacity investment， but it may also provide policy and market benefits， such as tariff reductions， tariff exemptions， and consumer price premiums. When these benefits are granted only after a local content threshold is met， firms may no longer adjust their production shares smoothly. Instead， they may increase local investment to cross the threshold or adopt a just-qualified localization strategy. Motivated by this issue， this study develops a two-stage decision model to examine local capacity investment and production quantity decisions of a multinational manufacturer under tariffs， local content thresholds， and consumer price premiums. In the first stage， the firm determines its level of local capacity investment. In the second stage， it determines the optimal local and offshore production quantities. Offshore production exported to the target market is subject to ad valorem tariffs. The model is solved by backward induction to show how tariff policies and localization requirements jointly influence firms’ investment incentives and production quantity decisions， and to provide insights for both managerial strategy and policy design.
