Adam Smith concludes his chapter on bilateral trade treaties — Chapter 6 of Book IV of The Wealth of Nations — with a detour on the practice of “seigniorage”. In summary, seignorage refers to the portion of metal retained by a sovereign (the government mint authorized to produce coins) when minting bullion into coins, i.e. the difference between the face value of these coins and their production cost. (As an aside, no less a figure than Sir Isaac Newton was appointed Master of the Royal Mint in 1699, a lucrative post he held for almost 30 years! See, for example, this fascinating 2022 paper by Alice Marples on “The science of money: Isaac Newton’s mastering of the Mint.”)
But Smith’s true target in this chapter is “that most insignificant object of modern policy” and “this silly notion”, the balance of trade. (WN, IV.vi.13 & 14) Why is the doctrine of the balance of trade so silly and insignificant in substance for Smith? The Scottish philosopher gives two reasons for this conclusion. One is that even if a country does end up importing more gold and silver coins from foreign countries than she exports abroad, some fraction of those coins will end up being melted down and exported abroad anyways. (WN, IV.vi.18) The other reason is that “no precaution of government could prevent it [i.e. the melting down of coins].” (ibid.)
But what does Smith’s critique of the balance of trade doctrine have to do with seignorage? The connection is this: Smith concedes that “a seignorage is the most effectual preventative of the melting down of the coin” (WN, IV.vi.21) He therefore devotes the last part of this chapter to the following question: how high or low should this seignorage be? That is, what is the optimal level of seignorage? If the seignorage is too low, it will not stop enterprising arbitrageurs from melting down minted coins and exporting them abroad, but if the seignorage is too high, the face value of such minted coins will not reflect their true value. In the end, Smith concludes that the seignorage of his day is a futile and ineffectual practice:
“If there was a reasonable seignorage, while at the same time the coin contained its full standard weight, as it has done very nearly since the last recoinage, whatever the bank might lose by the seignorage, they would gain upon the price of the bullion; and whatever they might gain upon the price of the bullion, they would lose by the seignorage. They would neither lose nor gain, therefore, upon the whole transaction, and they would in this, as in all the foregoing cases, be exactly in the same situation as if there was no seignorage.” (WN, IV.vi.26)
Is Smith’s survey of seigniorage still relevant today? Although the mechanics of 18th-century coin production have changed (the United States, for example, abandoned the gold standard in the 20th century), I suspect that Smith’s survey — and his analysis of money in Book I of his magnum opus — might shed some light on the mysterious economics of cryptocurrency.









