delivered the opinion of the Court.
The question here is the extent of the petitioner’s liability for a tax under §§ 501, 506 of the Revenue Act of 1932, 47 Stat. 169, which imposes a tax upon every transfer of property by gift, “whether the transfer is in trust or otherwise, whether the gift is direct or indirect, and whether the property is real or personal, tangible or intangible; ...”
The petitioner, age 72, made an irrevocable transfer in trust of 3,000 shares of stock worth $571,000. The trust income was payable to his wife, age 44, for life; upon her death, the stock was to be returned to the petitioner, if he was living; if he was not living, it was to go to such persons as his wife might designate by will, or in default of a will *178by her, to her intestate successors under applicable New York law. The petitioner, under protest, paid a gift tax of $71,674.22, assessed on the total value of the trust principal, and brought suit for refund in the district court. Holding that the petitioner had, within the meaning of the Act, executed a completed gift of a life estate to his wife, the court sustained the Commissioner’s assessment on $322,423, the determined value of her life interest; but the remainder was held not to be completely transferred and hence not subject to the gift tax. 40 F. Supp. 19. The government appealed and the Circuit Court of Appeals reversed, ordering dismissal of the petitioner’s complaint on the authority of its previous decision in Herzog v. Commissioner, 116 F. 2d 591. We granted certiorari because of alleged conflict with our decisions in Helvering v. Hallock, 309 U. S. 106, and Sanford v. Commissioner, 308 U. S. 39. In these decisions, and in Burnet v. Guggenheim, 288 U. S. 280, we have considered the problems raised here in some detail, and it will therefore be unnecessary to make any elaborate re-survey of the law.
Three interests are involved here: the life estate, the remainder, and the reversion. The taxpayer concedes that the life estate is subject to the gift tax. The government concedes that the right of reversion to the donor in case he outlives his wife is an interest having value which can be calculated by an actuarial device, and that it is immune from the gift tax. The controversy, then, reduces itself to the question of the taxability of the remainder.
The taxpayer’s principal argument here is that under our decision in the Hallock case, the value of the remainder will be included in the grantor’s gross estate for estate tax purposes; and that in the Sanford case we intimated a general policy against allowing the same property to be taxed both as an estate and as a gift.
*179This view, we think, misunderstands our position in the Sanford case. As we said there, the gift and estate tax laws are closely related and the gift tax serves to supplement the estate tax.1 We said that the taxes are not “always mutually exclusive,” and called attention to § 322 of the 1924 Act there involved (reenacted with amendments in § 801 of the 1932 Act) which charts the course for granting credits on estate taxes by reason of previous payment of gift taxes on the same property. The scope of that provision wé need not now determine. It is sufficient to note here that Congress plainly pointed out that “some” of the “total gifts subject to gift taxes . . . may be included for estate tax purposes and some not.” House Report No. 708, 72d Cong., 1st Sess., p. 45. Under the statute the gift tax amounts in some instances to a security, a form of down-payment on the estate tax which secures the eventual payment of the latter; it is in no sense double taxation as the taxpayer suggests.
We conclude that under the present statute, Congress has provided as its plan for integrating the estate and gift taxes this system of secured payment on gifts which will later be subject to the estate tax.2
*180Unencumbered by any notion of policy against subjecting this transaction to both estate and gift taxes, we turn to the basic question of whether there was a gift of the remainder. The government argues that for gift tax pur- . poses the taxpayer has abandoned control of the remainder and that it is therefore taxable, while the taxpayer contends that no realistic value can be placed on the contingent remainder and that it therefore should not be classed as a gift.
We cannot accept any suggestion that the complexity of a property interest created by a trust can serve to defeat a tax. For many years Congress has sought vigorously to close tax loopholes against ingenious trust instruments.3 Even though these concepts of property and value may be slippery and elusive they can not escape taxation so long as they are used in the world of business. The language of the gift tax statute, “property . . . real or personal, tangible or intangible,” is broad enough to include property, however conceptual or contingent. And lest there be any doubt as to the amplitude of their purpose, the Senate and House Committees, reporting the bill, spelled out their meaning as follows:
“The terms 'property/ 'transfer/ 'gift/ and 'indirectly’ [in § 501] are used in the broadest and most comprehensive sense; the term 'property’ reaching every species of right or interest protected by law and having an exchangeable value.”4
The Treasury regulations, which we think carry out the Act’s purpose, made specific provisions for application of *181the tax to, and determination of the value of, “a remainder . . . subject to an outstanding life estate.”5
The essence of a gift by trust is the abandonment of control over the property put in trust. The separable interests transferred are not gifts to the extent that power remains to revoke the trust or recapture the property represented by any of them, Burnet v. Guggenheim, supra, or to modify the terms of the arrangement so as to make other disposition of the property, Sanford v. Commissioner, supra. In the Sanford case the grantor could, by modification of the trust, extinguish the donee’s interest at any instant he chose. In cases such as this, where the grantor has neither the form nor substance of control and never will have unless he outlives his wife, we must conclude that he has lost all “economic control” and that the gift is complete except for the value of his reversionary interest.6
The judgment of the Circuit Court of Appeals is affirmed with leave to the petitioner to apply for modification of its mandate in order that the value of the petitioner’s reversionary interest may be determined and excluded.
It is so ordered.
The gift tax was passed not only to prevent estate tax avoidance, but also to prevent income tax avoidance through reducing yearly income and thereby escaping the effect of progressive surtax rates. House Report No. 708, 72d Cong., 1st Sess., p. 28; Brandeis, J., dissenting in Untermyer v. Anderson, 276 U. S. 440, 450; Stone, J., dissenting in Heiner v. Doman, 285 U. S. 312, 333.
It has been suggested that the congressional plan relating the estate and gift taxes may still be incomplete. See e. g., Griswold, A Plan for the Coordination of the Income, Estate, and Gift Tax Provisions etc., 56 Harv. L. Rev. 337; Magill, The Federal Gift Tax, 40 Col. L. Rev. 773, 792; Kauper, The Revenue Act of 1942: Estate and Gift Tax Amendments, 41 Mich. L. Rev. 369, 388; and see Commissioner v. Prouty, 115 F. 2d 331, 337; Higgins v. Commissioner, 129 F. 2d 237, 239.
2 Paul, Federal Estate & Gift Taxation, Chap. 17; Schuyler, Powers of Appointment and Especially Special Powers: The Estate Taxpayer’s Last Stand, 33 Ill. L. Rev. 771; Leaphart, The Use of the Trust to Escape the Imposition of Federal Income & Estate Taxes, 15 Com. L. Q. 587.
Senate Report No. 665, 72d Cong., 1st Sess., p. 39; House Report No. 708, supra, p. 27.
Treas. Regulations 79 (1936 Ed.), Arts. 2, 3, 17, 19. Cf. Commissioner v. Marshall, 125 F. 2d 943, 945.
The conclusion reached here is in accord with that of the several Circuit Courts of Appeals which have considered the problem: Commissioner v. Marshall, 125 F. 2d 943 (C. C. A. 2d); Commissioner v. Beck’s Estate, 129 F. 2d 243 (C. C. A. 2d); Commissioner v. McLean, 127 F. 2d 942 (C. C. A. 5th); Helvering v. Robinette, 129 F. 2d 832 (C. C. A. 3d), affirmed, post, p. 184; Hughes v. Commissioner, 104 F. 2d 144 (C. C. A. 9th); and see the cases cited in Note 2, supra.