臺灣上市與櫃公司除息日至發放間隔週期之研究

Comparing TWSE and OTC Firms on the Period between the Ex-date and the Payment Date

本研究應用行為經濟學觀點，說明公司除息日至發放日間隔週期決策是根據某個參考點延續或適度修正而來。對於首次發放股息之公司，參考點是同業或同集團之其他公司；再度發放股息時，參考點是公司過去之經驗，形成所謂的維持現狀偏好。本研究透過分析台灣上市櫃公司之發放股息資料（2009至2012年），證明：雖然經濟面因素導致上市公司發放股息傾向高於上櫃公司，但間隔週期決策導因於行為面因素，因此上市與上櫃公司形成相同之分佈特徵。本研究說明：一個月左右之間隔週期是公司依據經驗法則決策產生。雖然，一個月左右之間隔週期普遍被投資人認為是公平且正常之現象，卻未必是合理或最佳化之決策結果。就投資人與股東權益角度，合理之間隔週期應在28天之內。

This study examines the corporate decision of the periods between the ex-dividend date and the payment date from the perspective of behavioral economics. We find that the decision is based on a reference point from which an adaption is made to the market. The reference point for a firm initiating dividend payments is derived from that firm's past experience and other firms' past behavior, resulting in a status quo bias. By analyzing the payout policy by TWSE and OTC firms over the period 2009 to 2012, we find that TWSE firms are more likely to pay dividends based on financial factors, whereas the pattern of the periods between the two dates is consistent across the two markets. This similarity can be justified by behavioral reasoning. Although periods between the ex-dividend date and the payment date of one month are widely recognized as fair among market participants, it is not necessarily a just or optimal outcome. We demonstrate that decisions about periods between the ex-dividend date and the payment date are based on heuristics and argue that a just period should be less than 28 days.