Islamic Theoretical Intertemporal Model of the Current Account

This paper aims to develop an Islamic intertemporal model of the current account based on the prevailing theoretical and empirical literature of PVMCA (Obstfeld and Rogoff, 1996, Cerrato et al., 2014). The proposed model is based on the budget constraint of the present and future consumption, which depend on the obligatory Zakat from the income and assets, the return rate on the owned assets, the inheritance linking previous to subsequent generation. Using logarithmic utility function, featured by an unitary elasticity of intertemporal substitution and an unitary coefficient of relative risk aversion, we show through Euler equation of consumption that there is an inverse relationship between consumption growth from the last age to first one and the Zakat rate on assets. The outcomes of this result are that the Zakat on assets disciplines the consumer to have more rationality in consumption, and allows additional marginal assets for future generations. By assuming an unitary subjective discount rate, we indicate that more the return rate on assets is high, more the consumption growth between today and tomorrow will be fast. Through the budget constraint, if Zakat rate on the Zakatable assets is greater than Zakat rate on income, this leads to a relative expansion in private consumption of the wealthy group. Besides, we point out that an increase in return rate on assets, can drive to increasing or decreasing current consumption, because the substitution and income effects work in opposite ways.