Big data, financial services and privacy

DONALD TRUMP’s health-insurance premiums could soon go up, and not just because of his love of burritos. Data-crunchers have found a link between the negativity of someone’s tweets and his risk of dying of heart disease. The education levels of your Facebook friends or the activity on your phone can help reveal how likely you are to repay a loan. Money-managers are rummaging ever more curiously through customers’ digital lives.

This is all part of an “intensifying data arms-race in finance”, says Magda Ramada Sarasola from Willis Towers Watson, a consultancy, which claims that no industry used more big data last year. Banks and insurers used to rely only on what customers and credit agencies told them, but today websites and mobile-banking apps let them get much more close and personal. Less conventional sources are also popular. Social-media profiles, web-browsing, loyalty cards and phone-location trackers can all help. In a trial, FICO, America’s main credit-scorer, found that the words someone uses in his Facebook status could help predict his creditworthiness (tip: avoid “wasted”). Even facial expressions and tone of voice are being studied for...