It is clear what can and what cannot be done with fiscal policy

F iscal deficit s can be run under two circumstances: To correct fluctuations in private sector savings and investment rates: it would be perfectly normal to correct abnormal and transitory excess private savings through a fiscal deficit; To finance public investment or boost private investment whose returns are higher than the cost of public debt, or which generate positive externalities (for the climate, the economy, etc.). But fiscal deficits should not be used to finance current public spending that does not generate externalities and benefits only those economic agents who receive this public money: low-income support, pension system deficit s , keeping energy prices artificially low, etc.