"During the last ten years there has been dramatic changes in the ownership of commercial real estate in Sweden. This development has lead to a number of different discussions. One question is why Sweden has been so interesting and typical answer is that the market is comparatively transparent and that the liquidity is good. The focus in this article is however if these changes can be explained from an efficiency perspective. If we look at the world from a neo-institutionalist transaction cost perspective we should expect that more rational structures replaces a less rational structure. The buyers are obviously willing to pay more than the sellers demand: the properties are worth more to the buyers than they were for the sellers and on the most general level this should imply that the buyers in some way can get """"more"""" out of the properties. The question is then if it possible to find such rational factors behind the ownership or whether they seem to be driven by other factors. The current financial crises can be expected to lead to new patterns of ownership changes and can therefore be especially interesting to try to sum-up the development in the decade before this crisis."