The purpose of this Policy brief is to present an estimate of the fiscal space for a new stimulus plan in France that takes fully into account the impact of the low interest rate environment. Negative rates should lead to a different way to measure the public debt, a method that complements the Maastricht measurement. An alternative measure of the cost of the debt should take stock of the low interest rates and the repurchase of public debt by the central banks. The public debate is marked by some harmful confusion about the redistributive effects of public debt. First of all, it involves redistribution within each generation. An increase in public debt does not constitute a debt to future generations.