Final answer:
The current account balance can be calculated using the national saving and investment identity. The formula is: Current Account Balance = Total Domestic Savings - Total Domestic Physical Capital Investment - Government Budget Deficit.
Step-by-step explanation:
The current account balance can be calculated using the national saving and investment identity. The formula is: Current Account Balance = Total Domestic Savings - Total Domestic Physical Capital Investment - Government Budget Deficit. In this case, the government budget deficit is $100 billion, total domestic savings is $1,500 billion, and total domestic physical capital investment is $1,600 billion.
Using the formula, the current account balance would be: Current Account Balance = $1,500 billion - $1,600 billion - $100 billion = -$200 billion.
If the investment rises by $50 billion, while the budget deficit and national savings remain the same, the new current account balance would be: Current Account Balance = $1,500 billion - $1,650 billion - $100 billion = -$250 billion.