An interesting legal opinion is buried at the bottom of the article "How much priority for pension payments?" at:
in the penultimate paragraph:
Mr. Cabaniss also pointed us to a recent article by Amy B. Monahan, a professor at the University of Minnesota Law School, in the Iowa Law Review. As the article abstract put it, "This Article demonstrates that by holding that benefits not yet earned are contractually protected, without explaining the basis for finding that such a contract exists, California courts have improperly infringed on legislative power and have fashioned a rule that is inconsistent with both contract and economic theory."