Impacts of Monetary Policy on Consumer Demand of High- and Low-Income Groups in Indonesia

The research reported in this paper examines how changes in liquidity (or flows of financial services from monetary assets) affect commodity prices, levels of consumer expenditures on commodities, and the abilities of consumers in high- and low-income groups in Indonesia to adjust shares of expenditures to optimize their welfare (utility). A dynamic system of demand equations for each income group is specified on the basis of Cooper and McLaren’s (1992) Modified Price-Independent Generalized Logarithmic (MPIGLOG) demand system and Anderson and Blundell’s (1983) disequilibrium adjustment mechanism. A bloc of dynamic price equations is also specified, based on the principle of excess demand adjustment. In the model, income groups adjust their shares of aggregate expenditures on food, housing, and other items to partial-equilibrium levels, given commodity prices and the groups’ respective allocations of aggregate expenditures. Changes in the rate of growth of the supply of base money, determined by Bank Indonesia policy, influence changes in prices and income groups’ commodity expenditure levels, hence, levels of welfare derived from the consumption of commodities. The continuous-time model is estimated with annual time-series data on expenditures, prices, and financial aggregates by a non-linear quasi-Newton-maximum-likelihood procedure. The estimation results suggest that the demand systems for the two income groups studied in Indonesia are different but that adjustments in prices and consumption expenditures of both income groups have been affected by monetary policy. Counterfactual simulations of variations in monetary policy suggest that changes in the historical rate of growth of the money supply would have had discernibly sizable effects, that income groups would have been affected differently, and that increasing rates of growth of money would not have necessarily led to increasing prices for all commodities.