Answer: GDP increases by $100B
Explanation:
The Balanced Budget Multiplier is used to.measure the effect of a simultaneous increase in Government Spending and Taxes on the Economy.
While Classical Theorists believed that they cancel each other out, Keynesian Economists went about proving that this was not the case.
They showed that an increase in Government Spending had a ripple effect that was not curtailed by increasing taxes.
What they found out was that, increasing Government Spending at the same rate as taxes led to a rise in National income that was the same as the amount that Government Spending increased by.
This means that an increase in Government Spending and tax of $100 billion will lead to an increase in Income of $100 billion as well which will be translated into the GDP.