THE way that black holes bend light’s path through space cannot be smoothed out by human ingenuity. By contrast, a vast distortion in the world economy is wholly man-made. It is the subsidy that governments give to debt. Half the rich world’s governments allow their citizens to deduct the interest payments on mortgages from their taxable income; almost all countries allow firms to write off payments on their borrowing against taxable earnings. It sounds prosaic, but the cost—and the harm—is immense.
It's bizarre how people seem over-motivated by writing off their mortgage interest on taxes. It really does work to encourage people to assume more debt.