Economists are very good at saying that something cannot go on forever, but not so good at saying when it will stop.
If a thing can't go on forever, it will eventually stop.
Consumer: A person who is capable of choosing a president but incapable of choosing a bicycle without help from a government agency.
Trends that can't continue, won't.
If something is inevitable, it will happen
If you asked a sample of Americans "What is the temperature of Mars?" about 8% would say they don't know.