For years we’ve read that the US faces a looming shortage of nurses. Shortfalls in the hundreds of thousands of nurses are routinely predicted. These predictions have been good for nursing schools, which have used the promise of ample employment opportunities to more than double the number of nursing students over the last 10 years, according to CNN.

Yet somehow 43 percent of newly-licensed RNs can’t find jobs within 18 months. Some hospitals and other employers openly discourage new RNs from applying for jobs. That doesn’t sound like a huge shortage, then does it?

But the purveyors of the nursing shortage message have an answer for that. Actually two answers: one for the short term and another for the long term. The near term explanation is that nurses come back into the workforce when the economy is down. Nurses are female and tend to be married to blue collar men who lose their jobs or see their hours reduced when the economy sours, we’re told. Nurses bolster the family finances by going back to work — or they stay working when they were planning on quitting. There’s something to that argument even if it’s a bit simplistic.

The longer term argument is that many nurses are old and will retire soon, just when the wave of baby boomers hits retirement age themselves and needs more nursing care. Don’t worry, the story goes, there will be tons of jobs for nurses in the not-too-distant future. This logic comes through again in CNN’s story:

Demand for health care services is expected to climb as more baby boomers retire and health care reform makes medical care accessible to more people. As older nurses start retiring, economists predict a massive nursing shortage will reemerge in the United States.

“We’ve been really worried about the future workforce because we’ve got almost 900,000 nurses over the age of 50 who will probably retire this decade, and we’ll have to replace them,” [economist and nurse Peter] Buerhaus said.

I don’t buy this logic. And I stand by what I wrote almost a year ago in Nursing shortage cheerleaders: There you go again.

My issue with the workforce projections is that they don’t take into account long-term technological change, but simply assume that nurses will be used as they are today. I’ve taken heat for writing that robots will replace a lot of nurse functions over time. People seem to be offended by that notion and have accused me of not having sufficient appreciation for the skills nurses bring.

So let me try a different tack. Think about some of the job categories where demand is being tempered by the availability of substitutes. Here are a few I have in mind that have similar levels of education to nurses:

• Flight engineers. Remember when commercial jets, like the Boeing 727 used to fly with two pilots and a flight engineer? Those planes were replaced by 737s and 757s that use two member flight crews instead.
• Junior lawyers and paralegals. Legal discovery used to take up many billable hours for large cases. Now much of it is being automated
• Actuaries. Insurance companies used to hire tons of them, but their work can be done much more efficiently with computers

I don’t know exactly how the nursing profession is going to evolve but I do notice that the advocates for training more nurses are typically those who run nursing schools rather than prospective employers of nurses, such as hospitals.

If you want to be a nurse, go for it. But if you’re choosing nursing because you think it’s a path to guaranteed employment, think again.

David E. Williams is co-founder of MedPharma Partners and blogs at the Health Business Blog.