企業退休金計畫之動態選擇

Abstract

企業退休金計畫依給付方式的不同，可分為確定給付制與確定提撥制，以上兩種退休金計畫在承擔退休所得的風險上各有優劣不同。過去的二十年中，許多研究發現美國有越來越多的公司採用確定提撥制的退休金制度。雖然，絕大多數的研究同意這樣的趨勢，但是對於這個趨勢的成因卻始終沒有定論。有些研究主張這個趨勢的成因是因為確定提撥制取代了原有的固定給付制﹔另一些研究卻主張這個趨勢的成因是因為許多公司在主要的確定給付制之外，另外提供員工補助性的確定提撥制。這些過去的研究之所以得到不同的結果，其主要有兩個原因:一是他們在研究時往往忽略退休金制度是可以多重組合的﹔二是他們的研究資料多只是兩年之間橫斷面資料作比較。為了克服這些過去文獻的缺點，本研究蒐集從1985 到1996 年美國國稅局Form 5500 的資料建構一組panel data，追蹤每一年間公司對退休金計畫選擇的變化，並且利用Multinomial Logistic 回歸模型分析公司在退休金計畫動態選擇的改變與退休金計畫彼此間的互補與替代關係。本研究結果發現，在主要的退休金計畫階層(primary plan level)，由於成本考量因素，製造業的公司較可能從傳統的確定給付制轉換成確定提撥制；而大公司以及有工會的公司則較不會由確定給付制轉換成確定提撥制。另外，在次要的退休金計畫階層(supplementary secondary plan)，服務業的公司較可能在確定給付制之外成立補助性的確定提撥制；而有工會的公司則較可能在確定給付制之外成立補助性的401(k)制。

This paper examines the decision changes of employers’ pension plan choices during the trend from defined benefit (DB) to defined contribution (DC) plans. Multinomial logistic regression models were adopted to analyze the substitution and supplementary effects in both primary and secondary plan levels among existing 401(k), DB, and other DC plans. By using a completed 12-year panel data and controlling the drop-out and add-in firms, we provide new evidence of the dynamic changes for employer`s pension plan choices for survival firms. The empirical results shows that, compared to firms in other industries, firms in manufacturing industry are more inclined to change their primary plans from the DB to the DC plan; whereas bigger firms and unionized firms are more reluctant to do so. For the substitution and supplemental effects in the secondary plans, we find service related industries are more likely to supplement their primary DB plans with the DC plans, while are less inclined to supplement them with the 401(k) plans than the manufacturing industry. To the contrary, unionized firms are less likely to supplement their primary DB plans with the DC plans, but are more likely to have the 401(k) plans or both the DC and 401(k) plans