知識外溢及競爭壓力普遍被認為是影響廠商投入研發意願的重要考量因素，且兩外在因素與廠商投入研發的意願之間分別存在一致的反向關係。本文從投入足夠的研發可能驅逐其他劣勢廠商離開市場的觀點出發，重新檢視知識外溢及競爭壓力各自對優勢廠商研發意願的影響。結果發現優勢廠商會根據其研發效率採取不同的研發策略，且知識外溢或競爭壓力與廠商的研發意願並非皆呈現負相關。此一結果與以往研究與一般認知明顯不同。

Knowledge spillovers and competitive pressures are generally regarded as important variables of influencing the R&D incentives of firms, and there are usually negative relationships between them and the R&D incentives of firms respectively. This paper re-examines how the knowledge spillovers and competitive pressures affect the R&D incentives of one innovative firm respectively from the perspective that investing plenty of R&D may drive non-innovative firms out of the market. The major findings of this paper are that what R&D strategy being adopted by the innovative firm depends on its R&D efficiency and the relationship between knoledge spillovers (or competitive pressures) and the R&D incentives of the innovative firm may be non-negative. These results are quite different from the previous related studies and counter-intuitive.

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