| Private costs | met by producers | • labour costs • material costs | | --- | --- | --- | | External costs • negative externalities | spillover effects of production | • pollution (noise/ air/ water) → illness • resource depletion • traffic congestion • overcrowding | | Social costs | private costs + external costs | |

Private benefit met by consumers • happiness
External benefit
• positive externalities spillover effects of consumption • treatment of contagious diseases: prevent others from catching
• education: benefits community
• cycling: reduce pollution/ congestion
Social benefit private benefit + external benefit

Government policies to externalities