過去採用隨機邊界法估計薪資方程式和效率, 進而探討兩性薪資效率差異的 文獻, 皆未考慮樣本選擇問題, 本文採民國 94、96、98、100 與 102 等五個年度的
「人力運用調查」資料, 利用關聯結構法推導組合誤差間的聯合機率密度函數與概 似函數, 建構隨機邊界關聯結構模型, 解決勞動市場上樣本選擇性問題。分別估計 男性及女性隨機薪資與保留薪資 (工時) 邊界方程式, 進而探討男女性勞工的薪資 效率議題。接著提出 6 個假說, 將男、女性勞工按年齡、工作經驗、教育程度、工 作身分、婚姻狀態以及工作地分成 6 類, 分別比較與檢定薪資效率差異。為凸顯 考慮樣本選擇的重要性, 本文也將未考慮樣本選擇模型進行相同分析。
實證結果顯示,工作身分與工作地等 2 類, 不論有無考慮樣本選擇, 同一性別 的薪資效率變動趨勢大致一致, 但其餘 4 類, 考慮樣本選擇的薪資效率明顯不同 於未考慮樣本選擇。要而言之, 考慮樣本選擇之後, 壯年勞工的薪資效率最低、潛 在工作經驗年數較多者的薪資效率最高; 教育程度不論男或女性, 皆存在學歷愈 高, 薪資效率愈低的情況; 未婚女性薪資效率較已婚女性低、未婚男性薪資效率高 於已婚男性。以上發現有些與以往文獻相異, 他們未考慮樣本選擇是可能的原因之 一, 易導致係數估計值出現偏誤。
薪資不效率可能來自資訊不充分與性別差異, 政府應提供就業與失業者更多 就業資訊與職業訓練, 增加轉職與就業機會, 以利薪水提升, 降低薪資無效率程度。
至於性別差異方面, 宜透過教育灌輸性別平等觀念, 消彌薪資上的性別差異。
附錄一 𝜺 𝟏 = 𝑽 𝟏 − 𝑼 𝟏 之機率密度函數推導
對上式中的 z 積分可導得1的機率密度函數
附錄二 未考慮樣本選擇的係數估計結果
男性樣本對數薪資邊界方程式
94 96 98 100 102
cons 9.852*** 9.938*** 9.564*** 9.628*** 9.752***
edu 0.0169*** -0.0028 0.0304*** 0.0231*** 0.0058 edu^2 0.0023*** 0.0029*** 0.002*** 0.0022*** 0.0028***
dmarr -0.112*** -0.0719*** -0.0686*** -0.0827*** -0.084***
expe 0.0353*** 0.0341*** 0.0342*** 0.0319*** 0.0292***
expe^2 -0.0005*** -0.0005*** -0.0005*** -0.0005*** -0.0004***
ddmarrxexpe -0.0004 -0.0037*** -0.0031*** -0.0031*** -0.0013 sigu 0.346*** 0.274*** 0.286*** 0.227*** 0.271***
sigv 0.273*** 0.281*** 0.293*** 0.3*** 0.29***
女性樣本對數薪資邊界方程式
94 96 98 100 102
cons 9.594*** 9.639*** 9.362*** 9.536*** 9.496***
edu 0.0058 -0.0072 0.0162*** -0.0167*** 0.01 edu^2 0.0038*** 0.0041*** 0.0033*** 0.0045*** 0.0032***
dmarr -0.0794*** -0.0436** -0.0097 -0.0155 -0.0359*
expe 0.0259*** 0.0224*** 0.027*** 0.0281*** 0.0226***
expe^2 -0.0004*** -0.0003*** -0.0003*** -0.0004*** -0.0003***
ddmarrxexpe 0.0054*** 0.0027*** 0.0009 0.0008 0.0017*
sigu 0.417*** 0.325*** 0.354*** 0.286*** 0.337***
sigv 0.259*** 0.268*** 0.265*** 0.286*** 0.267***
附錄三 女性樣本之迴歸係數 – 考慮樣本選擇(加入子女數)
0 -32.9221*** -63.6843*** -19.4429*** -51.3894*** -73.4533***
lnH 7.8522*** 13.8564*** 5.1698*** 11.5041*** 15.4698*** Log-likelihood -31638.1 -31015.3 -30554.0 -30166.2 -29459.0
註：* 代表達到 10%顯著水準; ** 代表達到 5%顯著水準; ***代表達到 1%顯著水準。
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科技部補助計畫衍生研發成果推廣資料表
日期:2016/09/13
科技部補助計畫
計畫名稱: 應用關聯結構隨機邊界法探討我國勞工薪資低付與性別差異問題 計畫主持人: 黃台心
計畫編號: 104-2410-H-004-012- 學門領域: 人力資源
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