Why Blockchain's Salad Days Aren't Here Quite Yet

There’s been no shortage of excited pronouncements about how blockchain, the digital-ledger technology that makes Bitcoin work, will revolutionize everything from how stocks are traded to how Walmart Inc. keeps track of where that particular head of lettuce came from. Well, that lettuce-tracking blockchain is coming. But most of the other blockchain projects announced with enthusiasm in recent years aren’t, despite an estimated $2 billion invested by venture capitalists in the first half of 2018 alone.

It’s a tool that makes it possible for a large number of people or companies to record information collaboratively in a way that doesn’t permit tampering. Business transactions now are recorded in millions of electronic databases, each controlled by the company using it. (Remember Bob Cratchit, Scrooge’s clerk in "A Christmas Carol," slaving over paper ledgers? The integrity of the information he wrote down on the firm’s transactions rested on the fact that only he and Scrooge controlled them.) Blockchain is meant to open up that process.