Unlike with a variable-rate, Western-style loan, the borrower knows from the start how much the total payments will be (though of course fixed-interest loans are hardly unknown in the West).

ECONOMIST: A reader debate on Islamic finance

And the way the program works now, before these changes go into effect, is that the loan program has a variable rate with a cap of 8.25 percent.

NPR: How Cuts in Federal Aid Will Affect Students

The basis of any mortgage, whether you opt for a fixed, variable or tracker rate, is how you intend to repay the loan.

BBC: Mortgages explained for first-time buyers