When structural deflation appeared in the years following 1870, a common explanation given by various government inquiry committees was a scarcity of gold and silver, although they usually mentioned the changes in industry and trade we now call productivity. However, David A. Wells (1890) notes that the U.S. money supply during the period 1879-1889 actually rose 60%, the increase being in gold and silver, which rose against the percentage of national bank and legal tender notes. Furthermore, Wells argued that the deflation only lowered the cost of goods that benefited from recent improved methods of manufacturing and transportation. Goods produced by craftsmen did not decrease in price, nor did many services, and the cost of labor actually increased. Also, deflation did not occur in countries that did not have modern manufacturing, transportation and communications.