other property, no realization event occurs where this is no legal distinction between the exchanged properties. According to the Supreme Court in Cottage Savings, [u]nder our interpretation of § 1001(a), an exchange of property gives rise to a realization event so long as the exchanged properties are "materially different: they embody legally distinct entitlements. The facts in Cottage Savings present an example of realization occurring when property is exchanged for property. Cottage Savings Association (CSA) sold interest in home mortgages to four savings and loans associations. At the same time, CSA bought interest in mortgages held by the same four savings and loans associations. "The fair market value of the package of participation interests exchanged by each side was approximately $4.5 million." (Essentially, CSA and the four savings and loans associations exchanged $4.5 million worth of mortgage interests.) The Supreme Court held that a realization event under § 1001 had occurred: [b]ecause the participation interests exchanged by Cottage Savings and the other [savings and loans associations] derived from loans that were made to different obligors and secured by different homes, the exchanged interests did embody legally distinct entitlements. Consequently, we conclude that Cottage Savings realized its losses at the point of the exchange. Impact To suggest that Congress could tax unrealized gain is not to suggest Congress intends to do so. The realization requirement is a pervasive, popularly supported aspect of our tax system, and there is no indication Congress is about to reverse course in this regard. According to Burke and Friel, there are policy arguments to be made for and against taxing appreciation. If Congress chose to tax appreciation, taxpayers' tax income would likely match their economic income: "it would thus tend to place on the same tax footing persons who are economically similarly situated." However, the current system allows the IRS a degree of "administrative convenience." Moreover, it is arguably unfair to treat unrealized gains as income if the taxpayer may not have the appropriate funds to cover the tax liability, presumably forcing the taxpayer to sell the asset in question simply to pay the tax resulting from it. In the end, economic gain will be taxed. "Realization is fundamentally a matter of timing.... [t]he unrealized total gain, of course, may fluctuate from time to time as the property's value changes, but that total will be treated as income only on realization. To describe realization as a