How could popular intuition differ so sharply from the data? Beyond the yearning for simplicity, two more subtle missteps often play into trade balance reasoning. First, when we look at what goes into the GDP calculation, the accounting is as follows: GDP = C + I + G + (X − M) In this formula, C is consumption, I is investment, G is government spending, and (X − M) is exports minus imports (that is, net exports).