Money Market Equilibrium

What this diagram shows

The money market equilibrium diagram shows how interest rates are determined by the interaction between money supply and money demand. The vertical money supply curve reflects that central banks control the money supply independently of interest rates, while the downward-sloping money demand curve shows that people demand less money when interest rates are high (since the opportunity cost of holding cash increases). Where these curves intersect determines the equilibrium interest rate that balances the amount of money people want to hold with the amount available in the economy.

Key points

• Money supply (MS) is vertical because central banks set it independently of interest rates through monetary policy tools
• Money demand (MD) slopes downward because higher interest rates increase the opportunity cost of holding money, reducing demand
• Equilibrium occurs where MS intersects MD, determining both the interest rate and quantity of money in circulation
• Increases in money supply shift MS right, lowering interest rates; increases in money demand shift MD right, raising interest rates
• The diagram directly links to monetary policy transmission - central banks change MS to influence interest rates and economic activity

Exam board notes

All major exam boards treat this diagram identically in terms of basic structure. However, AQA and Edexcel place slightly more emphasis on linking money market equilibrium to the transmission mechanism of monetary policy, while OCR focuses more on the theoretical underpinnings of money demand.