Explain the importance of public finance in a welfare state.

Public finance — the state's money-science: the revenue's raising (the taxes-and-borrowing), the expenditure's spending (the services-and-investments), the deficits-and-debt's management — the government's household at the nation's scale. The discipline's branches (the lawyer's map): the revenue law (the taxes); the expenditure law (the budget-and-appropriation); the debt law; the fiscal-administration law (the departments-and-audit).