本篇論文由兩個議題組成，分別為產品市場競爭及產品集中度，並進一步探討對公司績效表現的影響。 第一個議題主要探討產品市場競爭對公司槓桿調整的影響。目前的文獻提供了產品市場競爭有利及不利的實證結果，然而對公司槓桿調整的影響仍尚未釐清。本研究結果發現，產品市場的競爭壓力會加速公司槓桿調整的速度。對於偏離(高於或低於)目標槓桿的公司皆有一致性結果，此結果顯示競爭程度能有效降低槓桿調整的成本進而增加槓桿調整的速度。本文進一步探討競爭壓力對槓桿調整速度的因果關係，採用美國製造業大幅降低進口關稅的準自然實驗(quasi-natural experiment)進行驗證，結果發現在大幅降低進口稅後，公司顯著提高槓桿調整。此外，公司治理程度較差以及能力較低的經理人會加強兩者的正向關係。總結第一個子議題，本研究證實產品市場競爭的有利面，能有效降低經理人與股東之間的代理衝突。 第二個議題探討客戶集中度是否影響股票市場流動性。由於主要客戶為了確保供應鏈的穩定性，他們會有動機進行監督並影響供應商的治理品質，進而提高供應商的股票流動性。實證結果發現，顧客集中度程度較高的公司會有較低的價差。本文採用不同的模型設定，內生性檢驗及穩健性測試後，結果仍一致。此外，客戶集中度有利於提高公司的經濟價值，主要顧客的監督行為能有效降低公司裁決性支出，違約風險，提高雙方的公司價值。總結第二個子議題，主要客戶具有較強的動機監督供應商以維持合作廠商體質健全，進一步從穩定的供應鏈關係中獲得利潤。;This dissertation consists of two standalone studies relating to product market competition, customer concentration and their effects on corporate performance. The first study examines the impact of competition in the product market on firms’ leverage adjustments. While recent research provides evidence of both the bright and dark sides of competition, its impact on firms’ leverage adjustments is an open empirical question. Results provide evidence that competitive pressures from the product market accelerate the leverage speed of adjustment (SOA) toward target capital structure. I obtain consistent results for both over- and under-levered firms, which implies that competition helps lower the leverage adjustment costs and hence increases the SOA, irrespective of whether firms are over- or under-levered relative to their target leverage. To establish the causal effect of competitive threats on the SOA, I exploit a quasi-natural experiment provided by large import tariff reductions in the U.S. manufacturing sector, and find a significant increase in firms’ leverage adjustments after large tariff cuts. The additional analyses reveal that the impact of product market threats on leverage adjustments is more pronounced for firms with poor governance quality and unskillful managers. Overall, this study highlights the “bright side” of product market competition and suggests that agency conflicts between managers and shareholders are attenuated by intensified competition. The second essay investigates the question of whether and how firm customer concentration impacts stock market liquidity. I hypothesize that to ensure supply-chain stability, principal customers increase incentives to monitor suppliers and exert influence on suppliers’ governance quality, thereby improving suppliers’ stock market liquidity. The empirical analyses document that firms with concentrated customer base are strongly and positively associated with narrower spreads. The main results are robust to a variety of model specifications and endogeneity concerns, and alternative proxies for stock liquidity. Further tests show that the increase in liquidity is mainly driven by supplier governance quality and customer bargaining power. In addition, I find evidence of economic benefits associated with the favorable effect of customer concentration along the supply chain. Customers’ monitoring efforts help reduce discretionary expenses, decrease default risk, and enhance firm value of both customers and suppliers. Overall, the findings from this chapter suggest that principal customers have strong incentives to monitor suppliers to keep their suppliers healthy, thereby gaining benefit from stable supply chain.
