There are good reasons for Maine communities to rely on the property tax for funding local government. It is a stable source of revenue, and unlike income and sales taxes, it doesn’t fluctuate wildly when the rest of the economy ebbs and flows.

But it can also be an unfair tax, because it puts a value on a piece of property regardless of its owner’s ability to pay. This has been especially hard for elderly people who would like to stay in their now-valuable property, but don’t have the money to pay the taxes without selling their home.

A bill designed to address the problem was passed by the Legislature this spring and was signed into law by Gov. Baldacci on Wednesday. It’s a small measure that could make a big difference in people’s lives.

The new law allows cities and towns to adopt ordinances permitting a taxpayer to defer what he or she owes until they die or sell the house.

To be eligible for the program, the homeowner has to be at least 70 years old, have lived in the home for at least 10 years, and have an income that is no greater than three times the poverty level.

This is fair to the municipalities, which can depend on eventually collecting the taxes owed, and it’s fair to other taxpayers, who will not have to pay higher rates to subsidize a neighbor.

But mostly it is better for elderly homeowners who have found that there is a big difference between property value and money in the bank. This way they can stay where they want to be and not be forced to sell their home until health or other reasons require it.

With all the pressures that come with age, this law will provide some comfort.