過去幾次對臺灣民眾的訪問調查研究發現：臺灣民眾的民族認同在過去十年間，歷經大幅度的變動：中國民族認同的穩定衰退、無特定認同的「現實主義」者持續成長、以及臺灣民族認同的勃興和歸於穩定。本文以一個追蹤訪問調查(1998/8-2000/12)的資料為基礎，除了指出臺灣民眾的民族認同非常不穩定之外，同時也以實證資料評估「族群文化認同」和「物質利益考量」這兩個因素，對臺灣民族認同態度之變動的影響。理性的「物質利益考慮」和「感情的歸屬」，是解釋認同本質的兩個對立理論。對「臺灣人」和「臺灣文化歷史」的宣揚，是興起中臺灣民族主義運動的主要基礎之一。可是臺灣民族主義運動同時也面對一個非常不利的局勢：中國軍事強權的威脅和中國經濟市場的吸引力。「中國因素」和「臺灣文化族群認同」這兩個方向相反的力量，對臺灣民族主義者有何影響？在臺灣民眾的認同中，麵包和愛情各發揮何種影響力？這是本文的主要問題意識。研究的初步發現是：就我們所研究的時間點而言，感情性認同吸力似乎大於物質利益的拉力。

The conflict of national identities has surfaced as the most salient issue in Taiwan's politics since the country became a full-fledged democracy in the late 1980's. The studies on nationalism in Taiwan have also been mushrooming in the recent years. Many previous studies have found a steady trend of identity change in the past decade among the general populace: the rise of Taiwanese identity with the decline of Chinese identity. Using the data collected in a panel study of interview surveys conducted in 1998 and 2000, this paper however finds the high volatility of national identity among the general public. Significant portions in all three major nationalist groups, namely the Taiwanese nationalists, the Chinese nationalists, and the pragmatists, had changed their identities in the period of two years. This paper also weighs the effects of material interests and affection as two contrary factors on the change of national identity. While the former, coming from the economic inducement of China, drags people away from the position of Taiwan independence, the latter, based on the cultural-ethnic identity with Taiwan, consolidates this position. This paper finds that in the particular period when the surveys were conducted, the consolidating effect of the ethnic-cultural identity on Taiwanese national identity seemed surpassing the straying effect of rational calculation of material interests.