An empirical study is conducted on scale and scope economies for Taiwan's banking industry with panel data using a Fourier flexible cost function developed by Gallant and a translog cost function, both of which take economic efficiency into account. It is found that the Fourier form is more appropriate than the traditional translog form in fitting the data, and that various efficiency measures computed using the Fourier function are compatible with each other, while those computed using the translog function are not. The Fourier evidence shows that sample banks continue to enjoy economies of scale, and exhibit scope diseconomies, which indicates that greater product diversification can reduce banking costs through product-mix economies. Banks may benefit from further diversifying their line of financial services.
