This paper tests the stability of the money-demand function in selected Central and Eastern European countries and investigates the extent to which money helps predict inflation. We first show that long-run money demand is better described with an open-economy model, which considers a currency-substitution effect, rather than the closed-economy model used in several previous studies. From the estimated models, we derive two measures of monetary overhang. Then we compare the ability of open-economy model and closed-economy model based measures of monetary overhang to predict inflation in the CEE countries (i.e., the Czech Republic, Hungary, and Poland). Whereas we cannot detect a significant difference in forecast accuracy between the two competing models, we show that the open-economy model based forecast model that reveals a stable long-run money demand encompasses the closed-economy model based version. jei 844 many empirical works on money demand, focusing on the interest-rate role and investigating the stability of money-demand functions. Several early studies (Budina et al. 1995, Narayn 2010) employed this closed-economy formulation to compute the stability of money demand in CEE countries. Other works (Dreger et al. 2007, Fidrmuc 2009) resorted to a general formulation of the money-demand function, as did Leventakis (1993), who also considered open-economy factors. Departing from extant empirical literature, we test the stability of money demand by comparing two competing models: the classic Cagan's (1956) closed-economy model (CEM) and Albulescu et al.'s (2018) open-economy model (OEM). This comparison allows us to explain the mixed findings reported in the existing literature about the stability of money demand.Additionally, the OEM model we use is a microfounded model, which differs from Leventakis's (1993) specification. It does not assume ex ante the existence of a direct currency substitution between domestic currencies and the euro. This model is compatible with both currency substitution and currency complementarity effects and is well adapted for CEE countries. It assumes that the euro offers liquidity services to the domestic representative agent, whereas the reverse is supposed not be true (for details, please refer to Albulescu et al. 2018). We resort to the Hansen's parameter instability test (Hansen 1992) to assess the cointegrating relationship and the stability of money demand. Furthermore, we estimate the long-run money-demand parameters with the fully modified ordinary least squares (FMOLS) method of Phillips and Hansen (1990).Another contribution of our paper is the identification of the monetary overhang, derived from the OEM and CEM long-run equations. 3 The purpose is to see to what extent the monetary overhang represents a good predictor of inflation in the Czech Republic, Hungary, and Poland from 1999 to 2016 (monthly data). Thus, we start from Stock and Watson's (1999) inflation-forecasting equation (i.e., out-of-sample and combined forecasting approaches). We further apply tests o...