Public Goods and imperfect Competition

Public good = non-excludable and non- rivalrous in competition

Merit good = good that can provided com[etently by the private sector wanted by society eg education

Demerit good= government restrict access eg fags 

Public goods, usually have positive externalities eg national defence 

Negative externality = too much quantity 

Positive externality = too little quantity

Perfect competition, no seller can influence = no market power 

Individual seller =  price taker 

Curve is horizontal 

Perfect competition; many small firms, identical production,perfect information, free entry and exit 

Social cost of monopoly