本文運用台灣人口資料，在假設「結婚利得及結婚意願」沒有下降的情况下，計算及推估2012年與2025年可婚指標（avail¬ability index），以比較兩年度男女的逐歲「絕對性擇偶機會」的升降。研究結果發現：（1）2025年未婚男性可婚指標在27至34歲高於2012年，但在39歲以後則明顯低於2012年。（2）2025年未婚女性可婚指標的最高雙峰仍停留在27與30歲，但是27歲以後可婚指標大多低於2012年。承上述兩點，近期年輕男女的未婚率的上升，縱使個人的原意只是推遲「正式考慮」婚姻擇偶年齡（想晚婚而非不婚），但將使更多男女發生「擇偶錯時」的情况（女性比男性嚴重），而在未來陷入比2012年「更劣勢」的婚姻市場中擇偶，使得男女結婚的困難度皆提提高。總結上述，近期年輕男女未婚率的上升，將不只導致未來男女的晚婚，而晚婚將進一步導致未來男女「不婚率」（40或50歲未婚率）的上升。台灣有婚姻意願但無法成婚的未婚男女將日漸增加，「未婚男女單身化」已是趨勢。另外，由於30歳以後女性未婚率的漸漸增加，這可能抵消政府獎勵已婚者多生的生育政䇿，台灣少子化現象在未來不易緩解。

This paper explored if the recent increase in the rate of unmarried young people will only result in a delay in marriage or also increase the number of elder single people in the near future. Taiwan’s availability index (Veevers, 1988) of 2012 and 2025 was calculated and estimated under the limitations of matching factors and the willingness to get married were kept unchanged, in order to assess the availability of men and women for marriage in the two years. The results show that in 2025, marriage opportunities are lower for both men and women as compared to 2012. Both men and women will be facing a higher proportion of “the predicament of mistimed mate selection.” Compared with 2012, the highest and second highest ages of the female availability index in 2025 stay the same. Accounting for the late marriage trend, the marriage age (or the mate selection age) in 2025 will more than the one in 2012. Therefore, women in 2025 might still seek a match, even when they have passed the highest age of the availability index, and are facing “the predicament of mistimed mate selection.” The male availability index after 34 years old in 2025 is slightly lower than the one in 2012. Overall, the results means that men and women will both face a more difficulty in matching. Hence, recent increase in the rate of unmarried young people in Taiwan will more likely to increase no-marriage of elder in the near feature.