Unit 4.3 - Glossary of key terms (Fiscal policy)A balanced budget exists if the value of the government"s revenues matches the value of its expenditure in a given time period.A budget deficit exists if the government spends more than it earns or collects (mainly in terms of tax revenues) for a given time period.A budget surplus exists if the government earns or collects more than it spends, for a given period of time.