UnitedHealth, the biggest insurer by revenue, is rolling out pay-for-performance contracts for hospitals, as well as testing its own medical homes and ACOs.

ECONOMIST: Health-care services: The good old ways | The

He made no secret of his belief that many teachers were incompetent, arguing in favour of testing them as well as pupils and of linking pay to performance.

ECONOMIST: Schumpeter

Fuel economy may suffer as well, so it is worthwhile to monitor your engine's overall performance while testing the lower-octane fuel.

WSJ: Is Regular Gas Good Enough?