Regulation and law.
Any subsidy or support provided by a governmental authority.
2. European Union (EU) law.
Under EU law, state aid is defined as an advantage, in any form, conferred on a selective basis by national public authorities, that distorts - or may distort - competition and trade between EU member states.
EU law generally prohibits state aid, while allowing exemptions.
Similar action and law in other jurisdictions.
For example the World Trade Organization's rules on state subsidies.