Tuesday the Washington Post’s fact-checker awarded three Pinocchios (“significant factual error and/or obvious contradictions”) to Mitt Romney’s claim to have created 100,000 jobs through his work at Bain Capital.

Meanwhile, Romney’s opponents were assailing him as a job destroyer, a “predatory corporate raider” according to a pro-Gingrich SuperPAC. Rick Perry accused Bain of looting companies and “getting rich off failure“.

Lost in all this attack-and-defense is the question: What does it mean to create a job, anyway? Let me repeat something I wrote a little over a year ago:

A bunch of factors need to come together to create a job. There has to be something worth doing, a worker willing and able to do it, a capitalist to pull together all the tools and materials of production, and a customer willing and able to pay for the product or service.

So the economic environment needs to supply an opportunity and people need to fill three roles: worker, capitalist, and customer. Conservatives assume that workers and customers always appear by magic, so a job is created whenever a capitalist shows up. If that were true, then conservative economics would make perfect sense: Keep rich people’s taxes low, and they’ll be able to fill the capitalist role in more and more places, creating more and more jobs.

In fact, though, any one of the three roles might be scarce. Picture a rural hospital that would love to have a cardiologist. The money and the customers are there, they just don’t have a worker. (We don’t usually think of cardiologists as “workers”, but they are.)

During construction booms, production might be held up by all kinds of worker shortages — plumbers, electricians, carpenters. Maybe the only thing holding up a new restaurant in Tulsa is that the local workforce doesn’t include the right kind of chef. In these cases, it’s the worker who is the “job creator”, not the capitalist. What triggers the existence of the job is the arrival of the scarce worker, who could be hired by any of a number of interchangeable capitalists.

In the recent recession, workers and capitalists have both been abundant, but customers have been scarce. Business Insider puts it like this:

If a company is going to hire someone, then a crucial question they must ask is: Is this person going to help make or do something that someone is going to buy. You can talk all you want about taxes or regulation, but if end demand for a product or service isn’t there, there’s no reason for a company to hire.

That’s the logic of stimulus: Put more money in people’s pockets and they will create jobs by becoming customers.

(That insight, by the way, provides the proper response to the slogan “I never got a job from a poor person”. You’ll also never get a job from a capitalist with no customers, no matter how rich he is or how little tax he pays.)

Finally, let’s consider the economic environment. Suppose a new interstate gets built, with an exit near a town that has a lot of unemployment. Three local businessmen want to build a fast-food franchise on a choice piece of land near the exit, and the Burger King franchisee outbids the McDonalds and Dunkin Donuts franchisees. So the Burger King gets built and employs 15 burger-flippers.

As soon as the new interstate changed the economic environment, all three roles were abundant. So who “created” those 15 jobs? The government did, by building the interstate. Government infrastructure projects have created jobs as far back as the Erie Canal, which made Buffalo into a grain-processing center.

But wait. Government can’t create jobs. Everybody knows that: Rick Perry, Ron Paul, Herman Cain, Eric Cantor, everybody. If you’re too stupid to understand why not, this conservative economist will explain it to you.

Maybe they all need to think it through again.

But let’s get back to the original topic: How many jobs did Mitt Romney create or destroy during the business career that netted him a quarter billion dollars?

Quite possibly none. If capitalists weren’t the scarce commodity in the deals he did, Romney might have been just another interchangeable cog in the economic machine. He probably is no more responsible for the jobs at Staples than the clerks who man the counters or the people like me who get our copying done there. Maybe the store would be in a different place, wear a different name, and employ different people, but as far as the overall economy is concerned it would make no difference.

Ditto for the job destruction in companies like AmPad. Money was there for pirates to capture, and there were plenty of them around. Mitt was the pirate who captured that particular treasure ship (and he’ll have to work out the ethics of it with his conscience and his God) but did he change anything? Ultimately, probably not.