Mistrust and low morale have become a byword for performance reviews at many big US companies as the `rank and yank' culture takes hold.

Don Schmidt, a family man with two daughters, spent his working life at the Ford Motor Company in Detroit. One day in November 2000, he discovered that the company had applied the brakes and he was facing the sack. Schmidt was a victim of something he couldn't control: his age. At 44, it seemed, he was just too old.