🧩 The Trading Puzzle

This story introduces the fundamental economic problem of "direct exchange," which is commonly known as barter. In an economy without money, barter is highly impractical due to the "coincidence of wants". This means that the item you want to buy is produced by someone who doesn’t want the item you have to sell. There is a lack of coincidence in scales, time frames, and locations. The only way around this severe inefficiency is "indirect exchange," where individuals use an intermediary good—a "medium of exchange"—that is widely accepted. Historically, humans converged on rare items like seashells to serve this purpose. Today, Bitcoin extends that same logic: it is the first medium of exchange whose scarcity is strictly limited and publicly verifiable — nobody can quietly create more of it.