Exhibit 11 WESTAMERICA BANCORPORATION Computation of Earnings Per Share on Common and Common Equivalent Shares and on Common Shares Assuming Full Dilution - ------------------------------------------------------------------------------ (In thousands, except per share data) 1996 1995 1994 - ------------------------------------------------------------------------------ Weighted average number of common shares outstanding 9,613 9,877 9,916 Add exercise of options reduced by the number of shares that could have been purchased with the proceeds of such exercise 177 164 83 - ------------------------------------------------------------------------------ Total 9,790 10,041 9,999 ============================================================================== Net income $37,740 $31,384 $27,662 Fully dilutive earnings per share ($) $3.85 $3.13 $2.77 Primary earnings per share ($) 3.93 3.18 2.79