multiplier effect on income

• what happens when there's an injection in the circular flow?

  actual change in national income>than initial injection called multiplier effect
• what does the size of the multiplier effect depend on?

  rate at which money leaks from the circular flow- e.g bigger the leakages, quicker the money leaves the circular flow and smaller the effect is
• if lots of money spent on imports, multiplier effect quite small as the injection quickly leaks