Equilibrium GDP for the open economy

Question

The data of columns 1 and 2 of the given table are for private closed economy. Open up this economy to international trade through including the export & import figures of columns 3 and 4.  Fill  up in columns 5 and 6 to find out the equilibrium GDP for the open economy. Describe why this equilibrium GDP varies from that of the closed economy.

Answer 1

Net export data for column 5 (top to bottom); $-10 billion in every space. Aggregate expenditure data for column 6 (top to bottom): $230; $270; $310; $350; $390; $430; $470; $510. For the open economy equilibrium GDP is $350 billion, $50 billion below the $400 billion equilibrium GDP for the closed economy. The $-10 billion of overall exports is a leakage which reduces equilibrium GDP by $50 billion.