For local public goods, supply or demand shocks may create periods during which it is welfare enhancing for households to undertake spatial arbitrage by relocating residentially. We point out that the magnitude and direction of the average benefit estimate obtained during such a transition period is likely to vary systematically depending upon the magnitude of the shock, the level of transaction costs and the extent to which other affected goods are substitutes or complements. We test a subset of our model's predictions using cross-sectional data on household demand for improved municipal services in post-socialist Romania. Our preliminary empirical analysis suggests that there have been substantial gains in welfare resulting from spatial adjustment following the opening up of housing markets. Furthermore, our results indicate that benefit estimates for improved water services during the transition may be substantially higher than long-run estimates. This limited evidence supports our concern that economists may recommend non-optimal levels of long-run investment, regulation, or user fees if they are unaware of the implications of future readjustment to supply or demand shocks.