It has also been incorporated against the states by the Fourteenth Amendment's requirement of due process.
- To eliminate a blight. Burban.
- To eliminate extreme wealth. Hawaii Housing Authority.
- To promote economic development. Kelo.
- Where "public necessity of extreme sort" requires collective action
- Where the property remains subject to public oversight after transfer to a private entity
- Where the property is selected because of "facts of independent public significance," rather than in the interest of the private entity to which the property is eventually transferred
These situations are valid public purposes under the federal restriction as well.
When the government does not condemn a property and take title of land in eminent domain proceedings but otherwise deprives a property owner's rights in a way that otherwise constitutes a taking, that landowner can initiate an inverse condemnation action to show that his land was taken, get it condemned, and get just compensation therefor.
Takings can occur when:
- The government actually condemns the property and takes title.
- The government conducts a permanent physical invasion of the property.
The standard for what constitutes a regulatory taking was established in Penn Central, which said that "economic impact of the regulation on the claimant and, particularly, the extent to which the regulation has interfered with distinct investment-backed expectations" must be balanced against "the character of the governmental action."
- The economic impact of the regulation on the claimant is determined by comparing the fair market value before and after the regulation.
- A buyer who purchases land already devoted to a legally permitted use usually has a reasonable investment-backed expectation that the use will continue.
- Again, when there is a physical invasion of the property, the Supreme Court has consistently held that a taking has occurred, regardless of how small a diminishment in value may result.
- A regulation is not a taking if it is reasonably related to the public health, safety, or welfare—even if it substantially diminishes the value of the affected land.
- The impairment must be truly significant to give rise to a taking.