Editor's Note: The following is a modified abstract of a paper presented at a conference held by Christ the King Law Center (CKLC) on October 8, 2016 titled Make America Catholic Again! Portions of this abstract were also taken from traditional Catholic attorney and author Christopher Ferrara's book The Church and the Libertarian: A Defense of the Catholic Church's Teaching on Man, Economy, and State.
And how would a Catholic state deal with the economy? When it comes to the so-called "free" market it would be subject to those legal restraints required by the moral order and natural justice, but men would otherwise be free to order their economic affairs. For example, the sale of immoral "goods" such as abortion pills, deadly drugs like heroin and PCP, contraceptives and pornography would be prohibited, as well as the provision of immoral "services" such as abortion and prostitution. Economic crimes such as false advertising, consumer fraud, price gouging, blackmail and bribery would be punished by public authority, either civilly (by actions for restitution and civil penalties) or criminally in accordance with the common law and other established legal traditions. Usury would be outlawed under local and state laws imposing limits on interest rates, which laws exist in many jurisdictions in the United States but have been superseded by federal law on account of lobbying by Big Finance.
Under local and state law employers would be required to allow the observance of the Sunday rest by employees, and communities would have the right to enact "Blue Laws" requiring the closing of retail businesses on Sunday-a legal measure still in effect in various American localities, such as Bergen County, New Jersey.  Local law, including zoning ordinances, would otherwise protect the character of the community.
 See "Blue Law," en.wikipedia.org/wiki/Blue_law, surveying the remaining state and local laws in this area.