Dissenting Opinion by
Mr. Justice Pomeroy :I join in the opinion of Justice Eagen and respectfully dissent from the decision of the majority which refuses to give effect to the so-called “blockage” factor involved in the valuation of large aggregates of stock for the purposes of the County Personal Property Tax Act (hereinafter “the Act”). Act of June 17, 1913, P. L. 507, as amended, 72 P.S. §4821 et seq. While I would affirm the order of the Superior Court on the basis of Judge Hoffman’s opinion, I deem it appropriate, in light of the Court’s opinion, to make certain observations which supplement those of Justice Eagen and of the Superior Court.
At issue in this appeal is the meaning of the term “actual value” of taxable property as used in Section 4.1 of the Act,1 for the tax made payable under the Act is calculated on the basis of that value. The taxable “value” of any property is measured in terms of the recognized medium of exchange, i.e., legal tender. This value is commonly established by the conceptual device of a hypothetical exchange of the property in question for legal tender on the relevant valuation date. The idealized transaction thus postulated establishes the “price which a purchaser, willing but not obliged to buy, would pay an owner willing, but not *566obliged to sell.” Deitch Co. v. Board of Property Assessment, 417 Pa. 213, 217, 209 A. 2d 397 (1965).
When the value of a security listed on a recognized stock, exchange is at issue, the terms of this hypothetical transaction are generally supplied by the stock market itself. Ordinarily, the best evidence of the price a willing buyer would pay and a willing seller would accept is . the closing price of that security on the relevant valuation date. This closing price is the result of actual transactions between buyers and sellers who are presumed to be under no compulsion. That price is a function, however, of the supply-and-demand factors operating in the market on the date in question, and any significant change in the supply of, or demand for, a security will be reflected in its price. Thus, if the sale of a large bloc of a security should occur in the absence of a concurrent compensating rise in the level of demand, the unit price of that bloc of securities would in all likelihood decrease.2 Consequently, when the transfer hypothesized in a valuation proceeding involves a large bloc of securities, determination of the value of that' bloc will necessarily entail consideration of the blockage factor. In such cases, therefore, the closing market quotation on a per share or per unit basis is the starting point for a determination of the actual value of blocs of securities; it is a point of reference rather than a final conclusion. What is being valued is a bloc, and not the individual units comprising the bloc.
*567The opinion of the majority apparently recognizes that blockage is a factor in the sale of large aggregates of stock; it asserts, however, that blockage should not be considered in personal property tax valuations for several reasons.
First, the majority argues that any deviation from the published closing price would create administrative difficulties of major proportions. I find no factual support for this contention. Our taxing authorities have proved able to overcome these burdens in the inheritance tax area where this Court has recognized the effect of blockage on the value of sizeable holdings in a single security.3 See Clabby’s Estate, 308 Pa. 287, 162 Atl. 207 (1932). Valuation of a security for which no public market exists creates a valuation problem similar to, if not more complex than, the one here in issue, but there is no sign that the administrative officers of the taxing authorities in this Commonwealth have been unable to cope with it. There is no showing, moreover, that the application of the blockage factor would be appropriate except infrequently.
The majority further asserts that “imponderables too numerous to mention” would be introduced into the valuation process if the closing price of a security is not to be the sole determinant of its taxable value. But these same factors have already influenced the quoted market price. Taxing officials need consider only the effect on that price of an excess supply of the *568security in question. This single-factor analysis is not a matter of insuperable difficulty; surely it is easier, for example, than the valuation of an equity interest in a closely held company, and that is a calculation frequently made by our taxing authorities.
The opinion of the Court assumes that valuation of assets for personal property tax purposes remains quite distinct from the situation under the Inheritance and Estate Tax Act of 19614 where, under Clabby’s Estate, supra, we have given effect to “blockage”. In the latter case, it is argued, an actual sale becomes contemplated, while in the former, the taxpayer holds the property for investment. Aside from the conceptual problems encountered in valuing any item of property without postulating a transfer thereof, the decision of the Court creates difficulty in reading too much into the inheritance tax legislation. The frequency of gifts of specific property and of elections to take in kind in estate distributions speaks against this imagined differentiation unjustified by any statutory language. Whether or not the owner of property contemplates sale seems a totally irrelevant matter in determining the objective valuation of the property in the theoretical market place.
Finally, the majority resorts to a supposed legislative intent in support of its conclusion that the term “actual value” means market price and that blockage should therefore not be allowed for purposes of personal property tax valuation. The statutory language makes no such intent apparent; and I personally doubt that the legislature had any intent on this issue one way or the other.
Mr. Justice Eagen joins in this opinion.72 P.S. §4843.1.
It should be noted that a bloe sale of securities will not always lead to a decline in the price per share. If the size of the bloc or the nature of securities is such that the bloc carries with it effective control of the enterprise, this control factor may well enhance the value of such securities, causing them to sell at a premium. The effect such bloc transfers have on- the selling price of a security is commonly referred to as the blockage factor.
In this connection, we note the practice under the Capital Stock Tax Act, Act of June 1, 1889, P. L. 420, as amended, and the Franchise Tax Act, Act of May 16, 1935, P. L. 184, as amended, 72 P.S. §1871, where the Commonwealth levies a tax on the basis of the “actual value” of a determined portion of the capital stock of a corporation. The average selling price on the market of such capital stock serves as only one factor for consideration of the value of the stock as a whole. See Act of June 1, 1889, P. L. 420, §20, as amended, 72 P.S. §1902.
Act of June 15, 1961, P. L. 373, as amended, 72 P.S. §2485-101 et seq.