The FASB's definition of assets needs to be revised because it confuses definition with measurement, stocks with flows, and it lacks empirical content. The definition cannot be used in practice to make clear distinctions between assets and expenses. A clearer distinction between assets and expenses would be possible if assets were defined as property-rights. All resources used by an enterprise have bundles of rights attached to them. These rights include the rights to use a resource, to change its form or substance, and to sell or rent it to others. If assets were defined as property rights, many of the costs that are deferred and recognized as separate assets under current GAAP would be eliminated.