Which raises the question, "Who the heck was Alexander Del Mar?" George S. Tavlas gives an lively and readable overview in "The Money Man" in the November/December issue of the American Interest.
Those who have heard of Del Mar make some striking comments about him. According to Tavlas, James Tobin called him "one of the most important U.S. monetary economists of the 19th century," while Robert Mundell called him “too hot to handle.” Among other professional accomplishments, Del mar was a co-founder in 1865 of the New York Social Science Review: Devoted to Political Economy and Statistics, often thought of as one of the first economics journals published in the United States. He was also the first director of the U.S. Bureau of Statistics in 1866--which later evolved into the U.S. Department of Commerce.
"He [Del Mar] referred to the example of the ancient states of Ionia, Byzantium, Sparta and Athens. As far back as the 10th century BCE, these states created huge discs of sheet iron or bronze that had no practical value but served as common measures of value against which all exchanges of goods could take place. In other words, Del Mar realized that money originated not to serve as a medium of payment in purchases (these discs were too heavy and bulky to be exchanged for goods), but to serve as a measure of value, or what economists call “a unit of account.” By establishing common units of account, early societies enabled the direct exchange of goods against goods to take place without the need for a physical object to be interposed as a medium of exchange. Del Mar saw that the existence of a unit of account is a necessary condition for the emergence of a full-fledged money economy ..."
Thinking of money as a unit of account for transactions and as a yardstick of value is standard fare in modern economics, but it was radical in Del Mar's time. However, these ideas are what led Del Mar to propose his rule that the government should guarantee that the supply of money would rise at 3% per year--which was Del Mar's estimate of the annual increase in the supply of goods and services each year. His proposal was well-timed, since in 1886 the U.S. economy was living through a period of ongoing deflation with periodic severe recessions. But his advice was ignored.
Why is Del Mar so little-known? Tavlas makes a case that part of the reason may be that Del Mar was Jewis, and overt anti-Semitism was common at the time among many economists and universities. Another reason is that, when it came to monetary theory, Del Mar was too far ahead of his time.