The United States at that time had neither gold nor silver regularly in circulation (except in California), and there was a long-continued discussion of "a return to specie payments," which meant the return to a metallic standard, and the redemption of greenbacks on demand. Meantime in 1873 a law was passed making the gold dollar "the unit of value," and dropping out the standard silver dollar from the list of coins authorized to be issued at the mint.[6] From 1873 until 1879, prices (in greenbacks) were falling in this country very rapidly because the country with the increase in population, wealth, and business, was "growing up to" its unchanging currency supply. For a like reason at the same time gold prices throughout the world were falling. While this country was lowering its level of prices from an inflated paper money to a gold commodity basis, the gold basis itself was sinking to a lower level. The very demand of our treasury and banks for gold caused the retention of our own gold product (which between 1864 and 1876 had been nearly all exported) and required an enormous net importation of gold between 1878 and 1888. This reduced suddenly by one-half the amount available each year from our production for the rest of the world. § 6. #Definition of the standard of deferred payments.# These various changes in the purchasing power of the standard money had great effects upon industrial conditions. Particularly had they shifted the positions and claims of debtors and creditors, because of the enormous importance of money as "the standard of deferred payments," Let us now get a more definite understanding of that term.