政治獻金對公司股價報酬之影響

Abstract

台灣每當選舉將至，政黨與企業關係就備受議論，總統對於整體產業和國家未來走向有顯著影響力，受到人民關注的程度也較高，故欲探討總統選舉之政治獻金是否對企業股價異常報酬率有顯著影響。本研究樣本時間至2020年台灣總統選舉，過去文獻觀察政治獻金少有將捐款公司之子公司、相關企業納入考慮。然而多數上市櫃公司於政治捐獻時往往不僅透過母公司，亦可能以關係企業為名進行捐獻，若遺漏考量非母公司捐獻數額則無法窺見政治獻金實則對公司股票價格之影響。本研究透過子公司關聯性比對，將政治獻金帳戶中各捐款公司數額歸類於其母公司，計算出上市櫃公司實際累計捐款金額，藉以確實探究政治獻金對於個別公司異常股票報酬之影響。綜合迴歸結果可以發現，當企業政治捐獻至當選政黨時，政治獻金越高對於公司股票之累積異常報酬率有顯著的正向影響，對於市值大、中、小之公司亦是如此，若捐款至當選政黨之金額前25%之公司，不同市值大小的公司呈現不同結果，對於市值大公司有負向影響，市值中和小公司則為正向影響，政治獻金對公司股價異常報酬在市值中小企業較為顯著。As election times approach in Taiwan, the relationship between political parties and enterprises becomes controversial. The president has a significant influence on the overall industry and the future direction of the country, and receives a higher degree of attention from the people. Therefore, this study aims to explore whether political contributions for the presidential election have a significant impact on the abnormal stock returns for enterprises.The sampling period of this study covers the 2020 presidential election in Taiwan. Past political donation related literatures rarely took the subsidiaries or affiliates of the donation company into consideration. However, when most listed or over-the-counter companies make political donations, they often donate through the parent company and under the name of affiliated companies as well. If the contribution amounts from non-parent companies are omitted, there is no way to observe the actual impacts that political contributions have on the companies’ stock prices. In this study, the researcher has compared the relevance of subsidiaries by attributing their political contribution donation amounts to their parent companies in order to calculate the actual cumulative donation amounts made by listed or over-the-counter companies.The goal is to explore the true impacts that political contributions have on the abnormal stock returns of individual companies. The comprehensive regression results indicated that when corporate political donations are made to the elected party, higher political donations have a significant positive impact on the cumulative abnormal stock returns of companies. This applies to companies with large, medium, or small market capitalization. For companies with donation amounts ranking among the top 25% of those received by the elected party, different market capitalization scales yield different results. The impacts tend to be negative for large market capitalization companies but positive for medium or small market capitalization companies. Political contributions tend to have more significant impacts in terms of abnormal stock returns for medium or small market capitalization companies.