Kate Walsh is president of the National Council on Teacher Quality.

Here’s something I’ve been struggling to understand: What makes the prospect of a national teacher shortage such an immediately compelling narrative, capable of spreading with the speed of a brush fire?

With almost no real data — because neither states nor the federal government collects the information that would be needed to pronounce the onset of a true teacher shortage — we witness the press, school districts, state school boards and even Congress conclude that we are in the throes of a full-blown national crisis.

At the root of this crisis is a New York Times news article published two summers ago reporting on six school districts that were having a tough time filling positions (though all but two ultimately started the year just fine). Whoosh! Overnight the teacher shortage became real.

That early spark was then steadily fed by news articles reporting that teacher preparation programs were facing unprecedented enrollment drops.

Nobody thought it important to consider that teacher preparation programs had for years been graduating twice as many teachers as are needed. According to findings from the American Institutes for Research, over the past 30 years, programs graduated between 175,000 and 300,000 teachers each year, yet consistently school districts have hired only between 60,000 to 140,000 newly minted teachers. Instead, school districts have been far more likely to hire people who already have some teaching experience. Federal data from 1999 to 2012 show that only about 30 percent of districts’ new hires were straight out of a teacher prep program.

The blaze reached new heights in September with a report from the Learning Policy Institute (LPI) producing a scary chart showing a widening gap between teacher supply and demand over the next five years.

But tweaking just one of the assumptions made by LPI leads to results that are altogether different. If we project an average class-size student-to-teacher ratio of 16 to 1 (which it is currently), rather than LPI’s estimate of 15.3 to 1, voilà!: The shortage disappears entirely.

What I find so frustrating about all of this is that we do actually have a huge, long-standing problem with teacher supply and demand. For 30 years, most districts in the nation have struggled to find enough certified secondary science and math teachers. And rural and urban districts have been unable to tap into a reliable and stable source of new teachers.

One answer to the problem is to pay such teachers more than others, but most districts continue to reject that solution because it is untenable with unions. We also could ramp up the availability of part-time positions for science, technology, engineering and math (STEM) teachers, but — again — few schools and states embrace this option because unions worry that districts will seek to replace full-time employees and their costly benefits with part-timers.

I’m inspired by what can happen when districts work smarter. Take Clark County, Nev., which faced a staggering 1,000 vacancies at the start of the 2015-2016 school year. The next year, district officials began the school year with nearly 700 fewer vacancies. How? They got smart about recruiting and negotiated a higher starting salary for new teachers. They targeted potential applicants from areas with notoriously high costs of living, telling them how they could live better on a teacher’s salary in Clark County. State efforts to ease certification requirements and improve certification reciprocity have also helped.

This is an approach that is eminently usable elsewhere.

We could also employ supply-side solutions. For decades, school districts have been awash with applicants for elementary teaching positions. That’s because teacher prep programs don’t see it as their job to tell incoming students they can’t all major in elementary education — that more of them need to consider special education, math or teaching English language learners, where there is real need.

Unfortunately, higher ed seems to accept no responsibility for aligning teacher production with district demand. Given that teacher prep programs can’t operate without state approval, states could impose limits on production in some areas.

The faux teacher shortage is of tremendous consequence. It routinely results in both states and school districts lowering standards for who is licensed and hired. But more important, it serves to distract us from fixing the chronic and persistent misalignment of teacher supply and demand.