sesses a full “bundle” of property rights, the destruction of one “strand” of the bundle is not a taking, because the aggregate must be viewed in its entirety. Compare Penn Central, supra, at 130-131, and United States v. Twin City Power Co., 350 U. S. 222 (1956), with Pennsylvania Coal Co. v. Mahon, supra, and United States v. Virginia Electric & Power Co., 365 U. S. 624 (1961). See also Michelman, Property, Utility, and Fairness: Comments on the Ethical Foundations of “Just Compensation” Law, 80 Harv. L. Rev. 1165, 1230-1233 (1967). In this case, it is crucial that appellees retain the rights to possess and transport their property, and to donate or devise the protected birds.
It is, to be sure, undeniable that the regulations here prevent the most profitable use of appellees’ property. Again, however, that is not dispositive. When we review regulation, a reduction in the value of property is not necessarily equated with a taking. Compare Goldblatt v. Hempstead, supra, at 594, and Hadacheck v. Sebastian, 239 U. S. 394 (1915), with Pennsylvania Coal Co. v. Mahon, supra.22 In the instant case, it is not clear that appellees will be unable to derive economic benefit from the artifacts; for example, they might exhibit the artifacts for an admissions charge. At any rate, loss of future profits—unaccompanied by any physical property restriction—provides a slender reed upon which to rest a takings claim. Prediction of profitability is essentially a matter of reasoned speculation that courts are not especially competent to perform. Further, perhaps because of its very uncertainty, the interest in anticipated gains has traditionally been viewed as less compelling than other property-related interests. Cf., e. g., Fuller & Perdue, The Reliance Interest in Contract Damages (pt. 1), 46 Yale L. J. 52 (1936).
22
It should be emphasized that in Pennsylvania Cod the loss of profit opportunity was accompanied by a physical restriction against the removal of the coal.