文獻上甚少提及廠商海外直接投資(outward foreign direct investments, OFDI)之群聚效應(clustering effects)對母國產品於地主國市場占有率的影響。有關這方面認知有限的原因，是因多數國家的廠商海外直接投資不會像台商IT上下游產業齊赴中國大陸投資並形成群聚現象。
本文擷取臺灣製造業中「赴中國與東協累計投資比重最高」、「最具出口競爭優勢」以及「產業間垂直整合與相互依存最顯著」的IT電子零組件製造業與電腦、電子產品及光學製品製造業，解析台商IT上下游產業在中國大陸(1992~2015)與東協五國(1999~2015)海外投資之群聚效應對臺灣IT產品於地主國市占率的之自我及交互影響，並就研究發現說明台商IT產業海外投資的管理及政策意涵。
研究發現：(1)台商電子零組件製造業與電腦、電子產品及光學製品製造業在中國大陸累計投資比重與臺灣零組件在中國大陸市占率成正向關係；(2)台商電腦、電子產品及光學製品製造業在東協五國累計投資比重與臺灣零組件在東協五國市占率成負向關係；(3)台商電腦、電子產品及光學製品製造業在東協五國累計投資比重與臺灣電腦、電子產品及光學製品在東協五國市占率成正向關係。
關鍵字：IT產業(IT firms)，海外直接投資(outward foreign direct Investments, OFDI)，市場占有率(market share)，群聚效應(clustering effects)
The industrial clustering of OFDI on home export to the market share in host market has been so far rarely explored in existing papers. One of the reasons for a lack of such research may be that there are none in the world like Taiwanese IT firms which have directed so much of their OFDI to China and have replicated industry clustering in China.
This study examines the clustering effec of OFDI in China and ASEAN 5 by Taiwan’s IT firms on the share of Taiwanese IT products in China and ASEAN 5 during the period of 1992-2015(China) and 1999-2015(ASEAN 5). The data are collected for electronic parts and components manufacturing and computers, electronic and optical products manufacturing that have the largest accumulative OFDI, have the most advantage in export competitiveness, and have the most significant clustering synergy from vertical integration and interdependence.
The results show that(1) the positive association of the assumulative OFDI in China made by both Taiwanese electronic parts and components & computers, electronic and optical products manufacturing to the market share of electronic parts and components in the China market;(2) the negative association of the accumulative OFDI in ASEAN 5 made by Taiwanese computers, electronic and optical products manufacturing to the market share of electronic parts and components in the ASEAN 5 market;(3) the positive association of the accumulative OFDI in ASEAN 5 made by Taiwanese computers, electronic and optical products manufacturing to the market share of the products of the kind in the ASEAN 5 market.
Keyword: IT firms, OFDI, market share, clustering effects
