r<g is an essay on the question whether r<g means the government can borrow and not worry about repaying debts. No. Abstract: A situation that the rate of return on government bonds r is less than the economy's growth rate g seems to promise that borrowing has no fiscal cost. r<g is irrelevant for the current US fiscal problems. r<g cannot begin to finance current and projected deficits. r<g does not resolve exponentially growing debt. r<g can finance small deficits, but large deficits still need to be repaid by subsequent surpluses. The appearance of explosive present values comes by using perfect-certainty discount formulas with returns drawn from an uncertain world. Present values can be well behaved despite r<g. The r<g opportunity is like the classic strategy of writing put options, which fails in the most painful state of the world. The essay is based on comments I gave at the spring NBER EFG meeting on Ricardo Reis' "The con...