本文探討當跨國廠商從事對外直接投資而面對較低廉的勞動成本時，是否會對其研發意願產生負面的影響。本文採用一個生產過程需要勞動與技術兩種投入要素的不完全競爭模型來進行分析。本文主要的結論如下：無論市場結構為何，當勞動與技術為互補性投入時，直接投資會使跨國廠商從事研發的意願提高；當勞動與技術為替代性投入時，直接投資對廠商研發量的影響方向並不確定。當地主國工資水準越低或市場規模越大，跨國廠商的研發量將越可能因直接投資而減少。當地主國廠商並未從事產品研發，若勞動與技術為互補性投入，競爭的市場結構會使跨國廠商因直接投資而引發的研發量較獨占時為高；若勞動與技術為替代性投入，競爭的市場結構不一定會比獨占更能提高因直接投資所引發的研發量。當地主國廠商亦從事研發競爭，若勞動與技術為互補性投入，地主國廠商的研發量必會因跨國廠商的直接投資而減少；若勞動與技術為替代性投入，跨國廠商的研發量因而減少時，地主國廠商的研發量有可能因跨國廠商的直接投資而增加。

The purpose of this paper is to examine whether a lower labor cost in the host country will negatively affect a multinational firm's R&D investment. An imperfectly competitive market structure and a production function with labor and technology in puts are utilized in this paper. The main findings in this paper are as follows. (1) If labor and technology are complementary inputs, the multinational firm will increase its R&D investment as it invests outward. (2) If labor and technology are substitute inputs, the impact of outward direct investment on multinational firm's R&D investment is ambiguous. It is shown that the lower the host country's wage or the larger the market size, the more likely it is that the multinational firm's R&D investment will decrease due to outward direct investment. (3) In the case that a host country's firm also invests in R&D, its R&D investment will decrease while facing foreign direct investment as labor and technology are complementary. On the contrary, as labor and technology are substitutes, the host firm's R&D investment may increase while facing foreign direct investment.