Justice Anthony Kennedy’s opinion for a 5-3 majority in the recently decided case of Murr v. Wisconsin continues the Supreme Court’s steady erosion of property rights. His embrace of yet another balancing test should concern defenders of constitutional rights in general.

The 5th Amendment to the U.S. Constitution forbids government taking of private property for public use unless the owner is compensated for the value of the property. Thus, if the government determines that it needs private property for a road or some other public facility, it must compensate the owners. This physical taking is usually accomplished in an eminent domain proceeding where the only matter in controversy is likely to be the value of the taken property.

Government officials don’t have to be particularly clever to recognize that they can often achieve their objectives through regulation rather than eminent domain, and thus avoid having to pay compensation. Where a government purpose does not require physical occupation of land — wildlife habitat protection, for example — a prohibition on use of private land is every bit as effective as public ownership.

To prevent such government circumvention of the takings clause, the Supreme Court ruled in the 1992 case of Lucas v. South Carolina Coastal Council that an unconstitutional taking of private property occurs when government regulation deprives the owner of all economically beneficial use. In the court’s terminology, both physical occupation and deprivation of all economically beneficial use constitute per se takings in violation of the 5th Amendment.

But the creativity of government regulators eager to avoid the expense of compensation knows no limits. For the purpose of preserving the scenic beauty of Wisconsin’s Lower St. Croix River, government regulators limited development to lots of at least an acre. The Murr family owns two adjacent lots of approximately 1.25 acres each, one acquired by their parents and the other by their parents’ company. When the two lots passed into the common ownership of the Murr children, the lots were said to be merged as a single parcel for purposes of the regulations. Thus, the Murrs were forbidden from selling one of the lots and they brought suit alleging an unconstitutional deprivation of all economically beneficial use of their property.

Justice Kennedy and the court’s four liberals ruled that the regulation did not deprive the Murrs of all economically beneficial use because they still had use of their cabin on what had been a separate lot prior to the regulation. For the purpose of determining whether there was a per se taking, concluded the majority, the separately acquired lots could be treated as a single lot.

Circumstances like those faced by the Murrs will not likely be common going forward. Property lawyers will take note of this decision and be careful to avoid common ownership of adjacent parcels. But the court’s ruling is nevertheless troubling. It is part and parcel of the court’s increasing reliance on balancing tests in the resolution of individual rights claims.

“The question of the proper parcel in regulatory takings cases,” wrote Justice Kennedy, “cannot be solved by any simple test.” Rather “courts must consider a number of factors” including “treatment of the land under state and local law; the physical characteristics of the land; and the prospective value of the regulated land.”

If the proper parcel under this new Murr test has no economically beneficial value as a consequence of the regulation, there will be a per se taking and compensation must be paid. But if the parcel as defined by the Murr test retains economically beneficial value, courts must then assess the economic impact of the regulation, the character of the regulation, and the extent to which the regulation interferes with reasonable investment-backed expectations under the 1978 Penn Central test.

So imagine that you own, or are contemplating purchasing, a parcel of land. What are your rights in relation to the government? There is no way to know with any certainty. If the government chooses to redefine the boundaries or restrict your use of your property, you must await a judicial balancing of a half-dozen factors to know whether you own what you thought you had purchased.

Balancing tests have become pervasive in constitutional rights jurisprudence. By substituting balancing tests for clear rules, judges effectively co-opt the legislative process by weighing the relative importance of various public policies. Worse yet, constitutional rights are made contingent on the policy preferences of unelected judges. Our constitutional founders must be turning in their graves.

Correction: The article has been updated to correct the name of the South Carolina Coastal Council.