In the United Kingdom, as in several other countries, increasing life expectancy is leading to a shift in the age distribution of the population. Meanwhile, at the level of individuals, spending patterns change as people age. This paper investigates the extent to which demographic change is likely to affect household spending patterns by combining the techniques of dynamic microsimulation with an imputation method known as random assignment. While there has been significant concern about the economic cost of the ageing population, this paper finds a potentially beneficial effect in the form of an increase in total spending for most expenditure categories.