This paper examines the long-run money demand function for 11 OECD countries from 1983 to 2006 using panel data and including wealth. The distinction between common factors and idiosyncratic components using principal component analysis allows to detect cross-member cointegration and to distinguish between international and national developments as drivers of the long-run relation between money and its determinants. Indeed, cointegration between the common factors of the underlying variables, i.e. cross-member cointegration, indicates that the long-run relationship is mainly driven by international stochastic trends. Furthermore, it is found that the impact of income on money demand is positive, while it is negative for the interest rate and stock prices. The estimated (semi-)elasticities of money are larger for the common factors than for the original variables, except the income elasticity. Finally, the results of a panel-based error-correction model suggest that money demand converges to an international cross-member equilibrium relation of the common factors.