Q. Which among the following is considered the main determinant of the level of income and output in Keynesian theory?
Answer: Aggregate demand (aggregate expenditure)
Notes: In Keynesian macroeconomics, equilibrium national income is determined by aggregate demand, also called aggregate expenditure. At the equilibrium level, total planned spending equals output and income. Taxation can influence aggregate demand, but it is not the primary direct determinant in the basic income-determination model.