The owners expect the price minus extraction costs to rise each year at the same rate as the rate of interest

The owners expect the price to rise over time until it reaches the choke price

The owners expect the choke price to be reached when the mineral resource is exhausted

In practice, the price may not rise steadily over time, but it will always rise

The income foregone while undertaking the education

The value of any extra enjoyment obtained from education beyond that which would be obtained from working

The fact that undertaking further education signals to employers that they are hard-working ad ambitious

Any scholarships or grants

It raises earnings more than most degrees

It raises earnings by about the average amount for all degrees

It raises earnings by less than most degrees

It has no significant effect on earnings

The incomes of different individuals

The incomes of different households

The incomes each household would need to maintain its present living standard if it comprised just one adult

The incomes each household would need to maintain its present living standard if it comprised just a married or cohabiting couple

Its original income is its income from earnings, investments and pensions other than State Pensions

Its gross income adds in transfers from the government

Its disposable income deducts taxes paid directly to the government

Its post-tax income deducts other taxes and adds in the value of government services received free of charge