What is the test for determining what is in the nature of income?

35. Here again, in view of the facts in Brown v. Helvering, it seems clear that in formulating a rule to determine what is in the nature of income, Brandeis J. referred to restrictions on the very right to dispose of an amount, not to restrictions on the way in which it is used.

36. What confirms my view is the restatement of this rule in Rutkin v. United States, 343 U.S. 130 (1952), affirmed in James v. United States, 366 U.S. 213 (1961), in which Warren C.J., at p. 219, cites the restatement in Rutkin, at p. 137: A gain "constitutes taxable income when its recipient has such control over it that, as a practical matter, he derives readily realizable economic value from it." This restatement of the rule for determining what constitutes taxable income emphasizes the benefit the taxpayer derives from income, whatever the way in which it is derived.