近來政府認為臺灣的銀行業競爭力不夠跟銀行過多有關，因此在政策上，希望藉由提高銀行集中度來降低市場競爭度，進而增加它們的競爭力。本文目的是以1996-2005 年臺灣銀行業的風險為研究對象，探討銀行集中度對銀行風險的影響。本文銀行風險強調的是以證券市場資料衡量的總風險、系統風險及非系統風險，並且在估計方法上，強調固定效果的兩階段最小平方法。主要實證結果發現，提高銀行集中度有助銀行的總風險及非系統風險的降低，以及銀行集中度對銀行總風險造成影響原因主要來自於非系統風險，而不是來自系統風險。

In recent year, the Taiwan government has concluded that the rather low
competitiveness of Taiwan’s banking industry is due to overbanking. To enhance the competitiveness in the banking industry, the government has aimed to lessen the market competition by increasing bank concentration. This paper presents an empirical study on the impact of bank concentration on bank risk in Taiwan from 1996 to 2005, and uses the equity market data to measure bank risks, which include total risk, systematic risk, and unsystematic risk. It also applies the fixed effects two-stage least squares technique for estimation. The results show that bank concentration is negatively correlated with both total risk and unsystematic risk. Furthermore, the negative correlation between bank concentration and total risk is due to unsystematic risk rather than systematic risk.