What is a National Saving and Investment Identity?

The national saving and investment identity provides a useful way to understand the determinants of the trade and current account balance. In a nation’s financial capital market, the quantity of financial capital supplied at any given time must equal the quantity of financial capital demanded for purposes of making investments.

How Does the National Savings and Investment Identity Affect Trade Deficits?

The national saving and investment identity also provides a framework for thinking about what will cause trade deficits to rise or fall. Begin with the version of the identity that has domestic savings and investment on the left and the trade deficit on the right:

Domestic investment – Private domestic savings – Public domestic savings  = Trade deficit