台灣上市企業於當地證券分公司發生異常交易量之決定因素：交易距離、當地偏誤、社群網絡與地區特徵

The Causes of Abnormal Volume of Taiwan Listed Companies in Local Securities Branches: Distance, Local Bias, Social Network, and Geographic Characteristics

本文從台灣證券市場交易距離探討異常交易量發生之因素，以台灣上市公司與各證券分公司之日內交易為研究樣本，衡量證券分公司與被投資公司距離及蒐集異常交易資料來分析當地偏誤現象，並應用區域人口統計、經濟活動與證券商特徵等探討當地偏誤之成因。實證結果發現被投資公司與當地證券分公司距離愈近時會產生異常交易，證實台灣股市確實存有當地偏誤情形。此外，不同的當地區域特徵分別對異常交易具有顯著影響，其原因可能與當地社群網絡、區域經濟發展與當地證券商所取得的資訊優勢有關。研究發現可提供給市場投資人投資決策參考，政府主管當局亦可據此管理市場內線交易，逐步改善證券市場交易制度，營造公正透明的證券交易環境。

This paper set out to investigate the relationship between distance and abnormal volume in Taiwan Stock Exchange. We take the intraday trading data of Taiwan listed companies and the branches of various securities firms as research samples, measure the distance between the branches of securities firms and the invested listed companies, and aggregate abnormal transaction data to analyze local biases, and apply local demographics, economic activities and characteristics of securities firms to explore the factors that form local biases. The empirical results show that the closer the investee company and local securities branch, the more abnormal transactions will occur, which confirms that there is indeed a local bias in Taiwan Stock Exchange. In addition, different local regional characteristics have significant effects on abnormal transactions, which may be related to the local social network, regional economic development, and the information advantages obtained by local securities firms. The research findings will provide investors with a reference for their investment decisions. The competent government authorities can also manage insider trading in the market accordingly, gradually improve the securities market trading system, and construct a fair and transparent securities trading environment.