Measuring Welfare in Dynamic Models with Externalities: Towards Money Metric Measures

This paper is concerned with welfare measurement in multisector dy-namic general equilibrium models with externalities. We start with the utility metric theory under di¤erent settings, and then transfer them into money metric measures. With ideal accounting prices for all externalities, we show that a money measure of dynamic welfare should encompass both the comprehenstive NNP and consumer surpluses. Under externalities, a forward-looking term reecting the present value of the future externalities has to be taken into account. For a local-in-time welfare comparison, we show that growth in conventionally measured NNP would work, provided that an externality-adjusted genuine rate of return is positive