In contrast, some Chinese studies have found no association between independent directors on the board and firm performance. For example, Gao and Ma (2002) selected a sample of 1,018 companies listed on both the local Chinese stock exchanges in 2001, 83 which had had independent directors on the board for at least three years. In this sample,they found no evidence to suggest that listed companies with independent directors on the board performed better than those without them. In addition, they found no significant relationship between the proportion of independent directors on the board and firm performance. Lu(2004) also failed to find any evidence of a relationship between firm performance and the proportion of inside directors, independent directors, or outside directors. A similar study by Sun and Zhang(2000) found that the proportion of independent directors on the board did not have any influence on Tobin's Q value, ROA ,or ROE. Bai et al.(2004) obtained a similar finding in their empirical study of Chinese listed companies between 1999 and 2001, in that the ratio of outsiders on the board did not have any significant impact on the firm value.