Key Takeaways
- Central bank grows money supply at fixed annual rate.
- Growth rate matches long-term real GDP growth.
- Avoids discretionary policy to reduce economic volatility.
What is K-Percent Rule?
The K-Percent Rule is a monetarist monetary policy concept proposed by Milton Friedman, which mandates that central banks increase the money supply by a fixed percentage annually, typically aligned with the economy's long-term real GDP growth. This consistent expansion aims to stabilize inflation and economic growth without engaging in discretionary adjustments based on short-term cycles.
This approach contrasts with active monetary policies that respond to business fluctuations, instead emphasizing predictability and limiting central bank intervention in line with principles of laissez-faire economics.
Key Characteristics
The K-Percent Rule is defined by several core attributes that prioritize stability and simplicity in monetary policy:
- Fixed growth rate: The money supply expands at a constant "k" percent annually, regardless of recessions or booms.
- Alignment with real GDP: The growth rate usually matches the average per capita GDP growth to maintain purchasing power.
- Rule-based policy: It reduces discretionary errors by central banks, promoting long-term economic predictability.
- Monetary stability: Aims to prevent inflation spikes by avoiding excessive money supply growth during economic expansions.
- Simple implementation: The rule avoids complex interventions like open market operations that adjust money supply frequently.
How It Works
Under the K-Percent Rule, the central bank increases the monetary base by a predetermined percentage, typically close to the economy’s average real growth rate, such as 2-4%. This fixed expansion disregards short-term economic indicators like unemployment or inflation spikes.
The mechanism relies on the assumption of a stable velocity of money, meaning that the speed at which money circulates remains constant. By matching money supply growth with economic output, the rule aims to maintain price stability and avoid the boom-bust cycles often triggered by active monetary policies.
Examples and Use Cases
The K-Percent Rule has influenced economic thought and monetary policy debates, though no major central bank fully adopts it. Some practical contexts include:
- U.S. Federal Reserve: While the Fed does not strictly follow the rule, its average money supply growth often tracks the U.S. economy’s real GDP growth, a concept central to macroeconomic policy debates.
- Airlines: Companies like Delta monitor macroeconomic trends, including monetary policy, to forecast demand and fuel costs in a stable inflation environment.
- Investment strategies: Understanding fixed money supply growth helps investors balance portfolios with assets such as those in low-cost index funds or bond ETFs to hedge against inflation risks.
Important Considerations
While the K-Percent Rule offers predictability and simplicity, it lacks flexibility during economic shocks like supply disruptions or financial crises. Rigid adherence may fail to address sudden changes in money demand or velocity, potentially causing recessions or deflation.
You should weigh the trade-offs between rule-based policies and discretionary interventions, considering that modern central banks often prefer inflation targeting or nominal GDP rules that allow adjustments. Still, the K-Percent Rule remains a foundational concept in macroeconomics and monetary theory discussions.
Final Words
Friedman’s k-percent rule offers a clear framework for steady monetary growth aligned with real GDP, reducing policy uncertainty and inflation risks. Consider monitoring central bank policies against this rule to gauge long-term economic stability prospects.
Frequently Asked Questions
The K-Percent Rule, proposed by Milton Friedman, is a monetary policy guideline where central banks increase the money supply at a fixed annual percentage rate, typically matching the economy's long-term real GDP growth. This steady approach aims to maintain economic stability by avoiding discretionary adjustments.
Unlike Keynesian policies, which adjust the money supply based on economic conditions like recessions or booms, the K-Percent Rule mandates a constant growth rate in the money supply regardless of the business cycle. Friedman argued this reduces policy errors and promotes long-term stability.
By aligning money supply growth with real GDP growth, the rule aims to keep the velocity of money stable and prevent inflation or deflation. This balance helps ensure that the money supply expands in line with actual economic output.
No major central bank has fully adopted the K-Percent Rule. However, its principles have influenced policies like inflation targeting. Central banks like the Federal Reserve have often deviated from it, especially during financial crises, by expanding money supply beyond the fixed rate.
The rule helps control inflation by providing a predictable, steady increase in the money supply, reducing the risk of policy mistakes caused by discretionary interventions. It also aims to promote long-term economic stability by preventing excessive monetary fluctuations.
If velocity drops unexpectedly, such as during hoarding, the fixed money supply growth could lead to mild deflation. Friedman considered this preferable to the instability caused by erratic monetary policies that overreact to such changes.
Friedman introduced the rule amid post-WWII inflation concerns and the end of the gold standard, aiming to limit political interference and central bank discretion. He viewed central banks as amplifiers of economic cycles and believed a fixed-rate money supply growth would reduce instability.


