Does there need to be a loser for every winner when it comes to investing and economic growth?

Topics covered include:

What are zero-sum games
How trading can be a zero-sum game
Why active management and seeking excess returns through security selections or country weights are zero-sum games
Why the U.S. stock market has outperformed the rest of the world
Why economic growth overall is not a zero-sum game, but some aspects of the economy are zero-sum games