Economists use changes in GDP to measure

the balance of trade with other countries.
any economic growth or shrinkage.
the causes of unemployment.
the distances between cities.

23. how does specialization among nations encourage interdependence? nations work together to share labor and resources to produce vital goods. nations sign treaties prohibiting taxes on imports. nations produce specific goods and then trade to obtain things they need. nations that are more developed agree to fund development in nations with limited industry.