considerable market value, that is not inventoried. There are, for example, coal lands, which are assessed for purposes of taxation at only a few dollars per acre, but which have a market value of many dollars per acre. In the previous census estimates of the wealth of the country this value has been presumably included under the head of real estate, but it is clear that any such record has been inadequate. I feel that my present estimates for the value of the mines of the United States are too low rather than too high. However, as between 1916 and 1920 they afford reasonable comparisons.
A side-light upon the shrinkage in mine value is to be found in the quotations for the shares of the copper producing companies, about 60 in number, that are listed on the exchanges. At the end of 1916 these reflected an aggregate value of 1.57 billion dollars. At the end of 1920 this was only $737,000,000. The market had therefore indicated a shrinkage of over $800,000,000 in copper mining companies alone. This is in no way to be regarded as a true measure. The market was not only reflecting the depletion of the mines and the deferral of dividends, but also somewhat of the surplus producing capacity that was destined to be written off. And withal it was possibly over-discounting all of those factors, amid the pessimism of the time and the exigencies of forced liquidation. Nevertheless, it is obvious that, even after making allowance for foreign companies included in the list of 60, the copper mines as a whole were enormously over-valued by the market at the end of 1916, no matter if the prospects for the industry were as good as they were then thought to be. Anyway, the
