This chapter concludes by considering the four main themes of the book: 1) How public spending has evolved over time, initially focussing on sound rules of the game and essential public goods and services before shifting more and more to welfare spending while debt grew to record levels.2) The huge differences in government performance and efficiency, the reinvigorating role of expenditure reforms and the pragmatic ‘optimal’ size of government, that does not require public spending of more than 30–35%, perhaps 40% of GDP.3) The main fiscal risks in the social and financial sphere from an ever-growing ‘insurance role’ of the state, which has contributed to rising debt and could put stability and sustainability at risk. 4) The case for strong rules and institutions to contain public spending, debt and fiscal–financial vulnerabilities. If governments focus on their core tasks and do them well, they underpin a well-functioning market economy with prosperity, freedom, opportunity and trust. This is the message of the social market economy model and it holds for the challenges related to the Coronavirus crisis which had broken out when this book went into publication. Not heeding this message in the past has contributed to governments being over-burdened and over-indebted today. We will all benefit from a lean, efficient and sustainable state.

Government expenditure needs to be financed. The two ways to do so are via taxes or via deficits and debt. For the first 90 of the past 150 years, public expenditure broadly grew in line with revenue, except during wars and times of crises. This changed fundamentally in the 1960s and early 1970s as the ‘Keynesian revolution’ took hold.Over the past fifty years, revenue rose strongly, but public spending often increased even faster. Chronic deficits stoked a high and growing stock of public debt in much of the advanced world. Public debt in the largest countries is now similar to the level prevailing at the end of the Second World War. Future governments will also face significant liabilities from increasing public expenditure related to population ageing, as well as fiscal risks from the financial sector. These liabilities and risks imply higher expenditure which will need to be financed. At the same time, there are political and economic limits to both taxation and indebtedness.

Financial sector developments pose the second important fiscal risk for the coming years and decades and this is the first of two chapters mapping and analysing such fiscal–financial risks. Rising financing costs affect debt service expenditure, especially for countries with high debt and short-term financing. Asset price movements can constitute further major fiscal risks in a downturn. Adverse financial sector developments and negative confidence effects also burden public expenditure and finances via the real economy, and guarantees that fall due in ‘bad’ times can exacerbate this effect. Debt has ratcheted up over consecutive economic and financial cycles over the past forty years, an effect particularly strong during the global financial crisis due to fiscal–financial linkages. Simulations show that the situation of several advanced countries is critical, given their lack of fiscal buffers for another crisis.