The future of money: four surprising ways we might pay for stuff in the next 15 years.

• Author: Schlegel, Heather

The dizzying rise of Bitcoin demonstrates that money can be more than just pieces of paper issued by central governments. As decentralized computerized networks proliferate, we have entered an era where middlemen are getting squeezed and consumer choice is multiplying. Governments have always wanted to maintain a strong grip on money--for tax purposes, if nothing else--but the way money is made, distributed, and valued could soon change drastically. Here are four (not mutually exclusive) ways money might mutate as we move into a future where convenience and choice are more powerful than government command.

1. TOTALITARIAN

   What Is It?

   A single currency that everyone everywhere uses for all legal transactions. All transactions are unavoidably recorded. Try to use another currency? You are ipso facto breaking the law, and you are suspected of using that currency for other illegal purposes.

   Such a universal currency need not be created by a global government. It could be a private digital currency closely tracked by a central oversight committee. Or it could run on autopilot, overseen by a nonprofit governance structure including representatives from communities, nations, and corporations--which might make it more palatable (though no less totalitarian) in a decentralized world.

   Where Does Value Come From?

   Government fiat. Legally, you must use it. With all transactions valued in a single currency, knowing the total worth of your holdings is convenient and easy. Despite centralized currency generation, prices would still be the result of decentralized choices of all currency users, as they are today.

   How Do You Get It?

   By selling a good or service.

   Does Government Control It?

   At the very least, government has a powerful seat at the table of the nonprofit producing the currency, with access to flagged transactions. If it doesn't own and operate the system, government will demand that transactions be transparent--or at least hilly accessible to its own agents.

2. HIDDEN

   What Is It?

   The descendant--or rather descendants--of today's Bitcoin. Rather than a single externally imposed universal standard, a diverse range of currencies follow predefined standards; together they make up an international currency consortium. Users don't have to pay active attention to currency transactions or conversions, because computer systems and algorithms will deal with them automatically. Anyone can create a currency/wallet/payment system as long as it adheres to...