GRESHAM'S LAW

INTRODUCTION

In economics, Gresham's law is a monetary principle stating that "bad money drives out good".

For example, if there are two forms of commodity money in circulation, which are accepted by law as having similar face value, the more valuable commodity will disappear from circulation.

GOOD MONEY & BAD MONEY

Good money is money that shows little difference between its nominal value (the face value of the coin) and its commodity value (the value of the metal of which it is made, often precious metals, nickel, or copper).

On the other hand, bad money is money that has a commodity value considerably lower than its face value and is in circulation along with good money, where both forms are required to be accepted at equal value as legal tender.

In Gresham's day, bad money included any coin that had been debased. Debasement was often done by the issuing body, where less than the officially specified amount of precious metal was contained in an issue of coinage, usually by alloying it with a base metal. The public could also debase coins, usually by clipping or scraping off small portions of the precious metal, also known as "stemming" (reeded edges on coins were intended to make clipping evident). Other examples of bad money include counterfeit coins made from base metal. Today all circulating coins are made from base metals, known as fiat money.

EXAMPLES

Silver coins were widely circulated in Canada (until 1968) and in the United States (until 1964 for dimes and quarters and 1970 for half-dollars) when the Coinage Act of 1965 was passed. These countries debased their coins by switching to cheaper metals thereby inflating the new debased currency in relation to the supply of the former silver coins. The silver coins disappeared from circulation as citizens retained them to capture the steady current and future intrinsic value of the metal content over the newly inflated and therefore devalued coins, using the newer coins in daily transactions.In the late 1970s, the Hunt brothers attempted to corner the worldwide silver market but failed, temporarily driving the price far above its historic levels and intensifying the extraction of silver coins from circulation.The same process occurs today with the copper content of coins such as the pre-1997 Canadian penny, the pre-1982 United States penny and the pre-1992 UK copper pennies and two pence.This also occurred even with coins made of less expensive metals such as steel in India.

THEORY

Gresham's law states that any circulating currency consisting of both "good" and "bad" money (both forms required to be accepted at equal value under legal tender law) quickly becomes dominated by the "bad" money. (For a formal model see Bernholz and Gersbach 1992). This is because people spending money will hand over the "bad" coins rather than the "good" ones, keeping the "good" ones for themselves. Legal tender laws act as a form of price control. In such a case, the artificially overvalued money is preferred in exchange, because people prefer to save rather than exchange the artificially demoted one (which they actually value higher).

Consider a customer purchasing an item which costs five pence, who possesses several silver sixpence coins. Some of these coins are more debased, while others are less so – but legally, they are all mandated to be of equal value. The customer would prefer to retain the better coins, and so offers the shopkeeper the most debased one. In turn, the shopkeeper must give one penny in change, and has every reason to give the most debased penny. Thus, the coins that circulate in the transaction will tend to be of the most debased sort available to the parties.

If "good" coins have a face value below that of their metallic content, individuals may be motivated to melt them down and sell the metal for its higher intrinsic value, even if such destruction is illegal. As an example, consider the 1965 United States half dollar coins, which contained 40% silver. In previous years, these coins were 90% silver. With the release of the 1965 half dollar, which was legally required to be accepted at the same value as the earlier 90% halves, the older 90% silver coinage quickly disappeared from circulation, while the newer debased coins remained in use. As the value of the dollar (Federal Reserve notes) continued to decline, resulting in the value of the silver content exceeding the face value of the coins, many of the older half dollars were melted down.Beginning in 1971, the U.S. government gave up on including any silver in the half dollars, as even the metal value of the 40% silver coins began to exceed their face value.

A similar situation occurred in 2007 in the United States with the rising price of copper, zinc, and nickel, which led the U.S. government to ban the melting or mass exportation of one-cent and five-cent coins.

In addition to being melted down for its bullion value, money that is considered to be "good" tends to leave an economy through international trade. International traders are not bound by legal tender laws as citizens of the issuing country are, so they will offer higher value for good coins than bad ones. The good coins may leave their country of origin to become part of international trade, escaping that country's legal tender laws and leaving the "bad" money behind. This occurred in Britain during the period of the gold standard.

THEIR'S LAW (REVERSE OF GRESHAM'S LAW) In an influential theoretical article, Rolnick and Weber (1986) argued that bad money would drive good money to a premium rather than driving it out of circulation. However, their research did not take into account the context in which Gresham made his observation. Rolnick and Weber ignored the influence of legal tender legislation which requires people to accept both good and bad money as if they were of equal value.They also focused mainly on the interaction between different metallic monies, comparing the relative "goodness" of silver to that of gold, which is not what Gresham was speaking of.

The experiences of dollarization in countries with weak economies and currencies (for example Israel in the 1980s, Eastern Europe and countries in the period immediately after the collapse of the Soviet bloc, or South American countries throughout the late 20th and early 21st century) may be seen as Gresham's Law operating in its reverse form (Guidotti & Rodriguez, 1992), because in general the dollar has not been legal tender in such situations, and in some cases its use has been illegal.

Adam Fergusson pointed out that in 1923 during the great Inflation in the Weimar Republic Gresham's Law began to work in reverse, as the official money became so worthless that virtually nobody would take it. This was particularly serious because farmers began to hoard food. Accordingly, any currencies backed by any sorts of value became the circulating mediums of exchange. In 2009 hyperinflation in Zimbabwe began to show similar characteristics.

These examples show that, in the absence of effective legal tender laws, Gresham's Law works in reverse. If given the choice of what money to accept, people will transact with money they believe to be of highest long-term value. However, if not given the choice, and required to accept all money, good and bad, they will tend to keep the money of greater perceived value in their possession, and pass on the bad money to someone else. In short, in the absence of legal tender laws, the seller will not accept anything but money of certain value (good money), while the existence of legal tender laws will cause the buyer to offer only money with the lowest commodity value (bad money) as the creditor must accept such money at face value.

The Nobel prize-winner Robert Mundell believes that Gresham's Law could be more accurately rendered, taking care of the reverse, if it were expressed as, "Bad money drives out good if they exchange for the same price."

The reverse of Gresham's Law, that good money drives out bad money whenever the bad money becomes nearly worthless, has been named "Thiers' Law" by economist Peter Bernholz, in honor of French politician and historian Adolphe Thiers."Thiers' Law will only operate later [in the inflation] when the increase of the new flexible exchange rate and of the rate of inflation lower the real demand for the inflating money."

APPLICATION

The principles of Gresham's law can sometimes be applied to different fields of study. Gresham's law may be generally applied to any circumstance in which the "true" value of something is markedly different from the value people are required to accept, due to factors such as lack of information or governmental decree. In the market for used cars, lemon automobiles (analogous to bad currency) will drive out the good cars. The problem is one of asymmetry of information. Sellers have a strong financial incentive to pass all used cars off as "good" cars, especially lemons. This makes it difficult to buy a good car at a fair price, as the buyer risks overpaying for a lemon. The result is that buyers will only pay the fair price of a lemon, so at least they reduce the risk of overpaying. High-quality cars tend to be pushed out of the market, because there is no good way to establish that they really are worth more. Certified pre-owned programs are an attempt to mitigate this problem by providing a warranty and other guarantees of quality.

"The Market for Lemons" is a work that examines this problem in more detail. Some also use an explanation of Gresham's Law as "The more efficient you become, the less effective you get"; i.e. "when you try to go on the cheap, you will stop selling" or "the less you invest in your non-tangible services, the fewer sales you will get." Vice President Spiro Agnew used Gresham's law in describing American news media, stating that "Bad news drives out good news," although his argument was closer to that of a race to the bottom for higher ratings rather than over and undervaluing certain kinds of news.

Gregory Bateson postulated an analogue to Gresham's Law operating in cultural evolution, in which "the oversimplified ideas will always displace the sophisticated and the vulgar and hateful will always displace the beautiful. And yet the beautiful persists."

Gresham's law has been cited as "Silver currency will inevitably force gold currency out of circulation" (L. Pyenson, Servants of Nature (W.W. Norton, 1999) p. 21); this suggests a fundamental misinterpretation, cf. Mundell.