The intellectual antecedent of positive accounting theory is the income smoothing hypothesis proposed by Gordon (1964). Within his framework, income smoothing emerges as rational behaviour based on the assumptions that (i) managers act to maximise their utility, (ii) fluctuations in income and the unpredictability of earnings are causal determinants of market risk measures, (iii) the dividend payout ratio is a causal determinant of share values, and (iv) managers' utility depends on the firm's share value (Beidleman, 1973; and Watts and Zimmerman, 1986, p. 134).