Bosses of biggest US groups suffer free falls to their pensions

Chief executives of the biggest US corporations saw their pay rise in 2015 at the slowest rate in seven years - but it's not because their boards were suddenly getting tough.

The main cause was something far more arcane: bond yields and interest rates.

The nominal amounts set aside by companies to cover pensions fell substantially last year, a result of rising bond yields and anticipation of the US Federal Reserve's first interest-rate hike in nearly a decade.