" Suppose there are only two firms in an economy: Cowhide, Inc. produces leather and sells it to Couches, Inc., which produces and sells leather furniture. With each $1,000 of leather that it buys from Cowhide, Inc., Couches, Inc. produces a couch and sells it for $3,000. Neither firm had any inventory at the beginning of 2006. During that year, Cowhide produced enough leather for 20 couches. Couches, Inc. bought 80% of that leather for $16,000 and promised to buy the remaining 20% for $4,000 in 2007. Couches, Inc. produced 16 couches during 2006 and sold each one during that year for $3,000. What was the economy's GDP for the 2006?"

Explanation: When calculating GDP, only finished goods are included in the calculation, items that are used to manufacture other goods are not included in the calculation of GDP.

Therefore, the leather that was bought to produce couches in 2006 will not be included in GDP, because its value is included in the value of couches.

Couches, Inc. produced 16 couches and sold them for $3,000 each, computing that, we have:

16 x $3,000

= $48,000.

However, inventory that Cowhide, Inc. has that is worth $4,000 was produced in 2006 as well, so it is included in the GDP. This item will be included in the GDP because it has not yet been bought to used in manufacturing another item. So the answer is $52,000.