The future of money is in your pocket — the one you keep your phone in, not your wallet. A growing portion of the world’s population is making phone-assisted transactions. They’re using a variety of technologies, from the text-message system popular in Kenya to the seamless credit card-and-app...

When factories belch smoke, everybody pays. Shouldn’t polluters be the ones to feel the sting instead? That’s the big idea behind carbon pricing: Add a levy so that emissions of greenhouse gases have a cost in line with their environmental damage. Using market forces should be the most efficient...