旗艦大學錄取的手足外溢效果之性別差異

Abstract

我使用台灣的行政資料研究兄弟姐妹在大學入學考試中過程中的外溢效果，以及這些家庭內部影響的可能機制。結果顯示，長子長女考上了旗艦大學，同一家庭的其他兄弟姊妹被錄取到同一所大學的機率將增加151％。當我分開估計長子跟長女的影響的時候，發現長子對於弟弟的影響結果是顯著的，顯示了手足外溢效果在兄弟之間高度集中，這一發現與兄弟之間競爭更激烈的假設一致。這種影響主要是通過兩個途徑實現的：一是弟弟在入學考試中取得更高的分數；二是他們在申請時更傾向於選擇旗艦大學。即使成績不變，高學業成就的訊號本身就足以在兄弟之間產生顯著的行為影響。

I use administrative data from Taiwan, where university admission primarily relied on a national entrance exam, to investigate sibling spillovers on admission to the flagship university and explore the potential mechanisms that deliver the within-family influences. Using an RD design, I find that having an older sibling being admitted to the flagship university increases the probability of admission to the same university by 151 percent. The spillover effect was highly concentrated between brothers, a finding consistent with the hypothesis that sibling competition is more intense between brothers than other sibling gender dyads. The estimated spillovers operated through young brothers achieving higher scores in the entrance exam (a performance effect), as well as lifting the ranking of the flagship university in their applications (a preference effect). My findings suggest that simply a signal of high academic achievement while holding scores constant, is sufficient to trigger significant behavioral influences between brothers.