網際網路的普及帶動電子商務的興起，本文藉由95年和100年工商及服務業普查，輔以個人家戶數位機會調查資料，分析民眾上網行為與市場結構的關聯性。本研究發現控制縣市別固定效果和時間的趨勢之後，各縣市民眾上網比例愈高，批發、零售業普遍地各類規模的廠商家數有減少的現象。在電子商務方面，研究結果顯示廠商提供在線銷售的服務能提高生產力，若再進一步討論電子商務的使用程度與生產力之間的關係，本研究發現有採用電子商務廠商的生產力以僅採用網路採購的效益最大，其次為同時採用網路銷售和採購，再者為僅採用網路銷售，完全沒有使用電子商務的廠商生產力最低。此外，本文亦探討網路銷售是否對不同規模廠商的生產力助益有所差異，結果證實規模較小和營運年數較長的廠商採用網路銷售對生產力的助益較大。而有關市場競爭程度方面，本研究發現批發廠商彼此間競爭程度愈大時，愈能提高廠商的生產力。然而，相反地，零售業較不受市場競爭的影響，但所在區域中若外資比重高能帶來正面的外溢效果，隱含主要的競爭來源可能是來自同區域的外資廠商。

This article explores how people’s online behavior impacts the market structure of wholesale and retail. After controlling for area and year fixed effects, we show higher fractions of consumers surfing the internet are associated with declines in the numbers of wholesale and retail establishments in the market. This paper also investigates the impact of e-commerce on labor productivity, using data obtained from industry, commerce and service census in Taiwan. The empirical results show that selling and buying goods or services online have a positive influence on productivity. It’s also found that small and older firms selling online exhibit higher labor productivity. As to the market competition, our results suggest that more competition raises labor productivity in retail, while there is no clear relationship between competition and productivity in wholesale. However, there exists positive foreign spillover effect if there is a large proportion of foreign corporation in the area. This may seem to imply the competition comes from foreign corporation in the same area.

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