This paper tries to provide an estimate of efficiency in eight Iranian banks, namely, Melli, Saderat, Mellat, Tejarat, Sepah, Refah, Keshavarzi and Maskan during 1996-2008, using the globally flexible Fourier Cost Functional Form and imposing theoretical regularities, discussed in Neoclassic microeconomic theory. One of the efficiency estimation methods is to estimate the cost function of ...