Opinion: Big data won't save you from coronavirus

Google can track your every move, but viruses don’t carry phones. Photo is of tourists in Red Square near the Kremlin in Moscow, Russia, on Jan 27. — Bloomberg

How often do you see a piece of economic or financial information revised upward by 45%? And how reliable would you regard a data set that’s subject to such adjustments?

This is the problem confronting epidemiologists trying to make sense of the novel coronavirus spreading from China’s Hubei province. On Feb 13, the tally there surged by 45% – or 14,480 cases. The revision was largely due to health authorities adding patients diagnosed on the basis of lung scans to a previous count, which was mostly limited to those whose swab tests came back positive.