Price comparison websites (PCWs) are great, says the Competition and Markets Authority (CMA). They really drive engagement and competition. Just a few minor issues worth investigating: who are they? Can they be trusted to display the real results of their comparison? Do commission payments influence them? Do they force out competitors by signing limiting deals with suppliers they list?

Seriously? But those are their only functions. If they get them wrong, there is nothing left. The ­investigation recently launched by the CMA is clearly sorely needed.