Urban economists understand housing prices with a spatial equilibrium approach that assumes people must be indifferent across locations. Since the spatial no arbitrage condition is inherently imprecise, other economists have turned to different no arbitrage conditions, such as the prediction that individuals must be indifferent between owning and renting. This paper argues the predictions from these non-spatial, financial no arbitrage conditions are also quite imprecise. Owned homes are extremely different from rental units and owners are quite different from renters. The unobserved costs of home owning such as maintenance are also quite large. Furthermore, risk aversion and the high volatility of housing prices compromise short-term attempts to arbitrage by delaying home buying. We conclude that housing cannot be understood with a narrowly financial approach that ignores space any more than it can be understood with a narrowly spatial approach that ignores asset markets.