Here’s an example from real life.
The manufacture and running of power boilers are generally not directly regulated by any state or federal agency in the United States. Fact. (Some states do have their own ‘boiler laws’, but those are very few and very exceptional – and in most cases even they defer to rules drafted by… boiler manufacturers.) Most states defer boiler inspections to the few insurance companies who regularly insure them, such as Liberty Mutual and Hartford Steam Boiler, who train and employ inspectors from coast to coast.
This all started back in the dawn of the Industrial Revolution when we first started using power boilers for driving steamships and railroads. There were a lot of problems, a lot of explosions and a lot of catastrophe from poorly manufactured (and operated) steam engines. (I think it was Huckleberry Finn where Mark Twain vividly re-creates a fairly typical incident: paddleboats racing each other on the Mississippi, and one of them blows up because of the excessive pressure generated during the race.)
The problems started to get worse as we started to make more and more massive power boilers to drive steam turbine-generator sets to produce electricity.
What happened was that the manufacturers, designers, constructors, owners and operators of the plants – and their insurance companies – got together and started what is now known as the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (“the Code” as we call it in the industry; it needs no more name than that, even though now the “Power Boiler” code is just “Section I” of a 12-section set of volumes, and other international codes also exist that do the same things that ASME does, in different ways). Over the years as materials, construction methods, techniques of operation, instrumentation and controls have all improved, so has the Code.
Boilers today operate at obscenely high pressures, at duty cycles that few other machines in our lives see, for decades at a time – and when was the last time you heard of one blowing up? Wherever you live in the world, probably the majority of your electricity is provided by steam-driven turbine-generator sets. (If they’re powered by nuclear-generated steam, that’s covered by Section III of the Code.)
And yet, membership is ASME is voluntary. Manufacturers are not required to have representation in it (although it is highly desirable), and subscription to it is optional – unless a manufacturer wants to stay in business. No one in North America will buy a non-ASME power boiler, even in the few places where they might possibly be able to. That’s because no insurance company would cover it, even if the state didn’t mandate that “boilers must be built and maintained according to the rules of ASME Section I”.
The private sector is absolutely a workable way to promote industry standardization on technical matters, self-regulation and promotion of new and improved technology. (We’re building boilers today that engineers weren’t even dreaming about 50 years ago, even though for my entire professional life I’ve thought “these things are dinosaurs; I can’t wait to see what will replace them… any day now…”.) And yet, we still build them bigger, and better (more efficient in extracting energy from fuel, and more powerful, to boot), and safer than ever.