Tim Harford: In truth, most people act in the public interest during a crisis. "...A mere three per cent of shoppers had bought “extraordinary amounts” of pasta. Most of us were merely adjusting our habits to life spent away from restaurants, sandwich bars and offices with their own loo paper. We all went shopping a bit more often, and when we did, spent a little more. No cause for collective shame, but it was enough to strain supermarket supply chains." Writing in the Financial Times, Tim Harford debunks those headline-grabbing myths.