Gresham's law
Gresham dynamic · bad money drives out good
Bad money drives out good, when both must be accepted at the same official value. People spend the debased coin and keep the sound one, so only the bad circulates — and the same happens wherever quality is unpriced.
In practice
If clients pay the same for careful work and rushed work, careful work stops being offered. The price has made the quality invisible, and the market clears on the cheaper version.
The common mistake
Applying it wherever quality declines. The law requires a forced exchange rate — the two things must be treated as equal in value by rule or by convention. Where buyers can discriminate on price, good drives out bad instead.
Named for Thomas Gresham, a sixteenth-century financier, though the observation is older: bad money drives out good.
When a government mints coins of the same face value but different metal content, people spend the debased ones and hoard the sound ones. Why hand over a coin worth more than its face value when a worse one settles the same debt? Within a short time only the bad coin circulates and the good has disappeared into drawers.
The condition everyone forgets
The law only works where the exchange rate is forced. The two coins must be legally equal in value despite being unequal in fact.
Remove that and the effect reverses. Where buyers can pay different amounts for different quality, good drives out bad, which is how markets normally work. So the interesting question about any Gresham situation is always: what is forcing the equal price?
Where the forced rate appears without a mint
Undifferentiated pricing in a market. If clients in a category pay one going rate regardless of quality, the careful supplier is subsidizing the careless one, and eventually stops being careful or leaves the category. The mechanism is the reason positioning is defensive as well as commercial — it is how you escape the forced rate.
Hiring at a fixed band. One salary for a role with a wide range of actual ability means the strongest candidates go elsewhere and the band fills from the bottom.
Unpriced internal quality. If a rushed piece of work and a careful one are received identically, rushed work wins, because it is cheaper to produce. This is what turns into process debt.
Attention. Where a channel treats every piece of content as equal, cheap content drives out expensive content, because both get the same distribution.
The escape
Make the quality visible so the rate is no longer forced. Signals, guarantees, specialization, references — everything on signaling exists to break exactly this equality.
If the quality cannot be made visible, then the market has a forced rate and the good version will leave it. That is a reason to change the market rather than to keep supplying the good version into it.
Concept web
Open the full webQuestions
What is Gresham's law?
That bad money drives out good when both must be accepted at the same official value. People spend the debased coin and keep the sound one, so only the debased version circulates.
When does Gresham's law not apply?
When buyers can pay different prices for different quality. The law requires a forced equal exchange rate; without one, good drives out bad, which is how markets normally work.
How does Gresham's law apply to services?
Where clients in a category pay one going rate regardless of quality, careful suppliers subsidize careless ones and eventually leave or stop being careful. Making quality visible through signals and specialization breaks the forced rate.