Money demand models overpredicted M2 growth in the United States from 1990 to 1993. We examine this overprediction using a model of household demand for liquid wealth. The model is a dynamic generalization of the almost-ideal demand model of Deaton and Muellbauer (1980). We find that the own-price elasticity of money demand rose substantially after 1990. We also find important cross-price elasticities of money with respect to other liquid financial assets, notably with respect to mutual funds. Incorporating these and other features helps explain nearly 50 percent of the shortfall in M2 growth over the period in question. It also suggests that households respond more rapidly to changes in market interest rates than is assumed in some limited-participation general equilibrium macroeconomic models.