>[!abstract] >The Harberger Tax, also known as Common Ownership Self-assessed Tax (COST), is a type of property tax that aims to improve societal welfare by optimising for both investment and allocative efficiency of private property. It proposes a new kind of "partial ownership", halfway between private ownership and common ownership. The tax is implemented by two mechanisms: >- Owners periodically self-assess their property and pay tax on its value. >- Others are able to purchase the property from the owner at the taxed price at any time, forcing a sale. > >(Wikipedia, 2025). >[!related] >- **North** (upstream): — >- **West** (similar): — >- **East** (different): — >- **South** (downstream): —