Competition among recruiters as the economy expands has pushed graduate salaries to an average of 28,000, up by 1,000 in a year.

The more confident households feel, the more they spend and the faster the economy expands.

The nation's 1.2 billion people rely on imported oil for 80 per cent of their requirements, which are rising sharply as the economy expands.

Weaker growth ahead - while the economy expands by only 1.6 per cent next year and 1.7 per cent in 2019 - means huge pressures on the state coffers will also continue.

For these reasons, when capital stock of an economy expands, entrepreneurs will only be able to use it at a lower marginal profit ratio.