Need a lesson on the problem with tax cuts? Ask a teacher.

The 40th anniversary of the passage of Proposition 13, the California tax limitation measure that spawned about a zillion mutant offspring nationwide, is just weeks away.

At the same time, teachers from Oklahoma and West Virginia to Highlands Ranch, Colo., are demonstrating at state capitols to demand a livable wage and decent working conditions.

Coincidence? I think not.

As tax revenues have shrunk, teachers have seen their paychecks and benefits evaporate, with compensation for Colorado teachers declining by 7.7 percent over the past decade. Consequently, teacher shortages are severe and districts across the state have reduced schedules to four days a week.

So what is a taxpayer — weaned on decades of seductive rhetoric that says tax cuts will make us all rich — supposed to think? Have we gone too far?

Maybe instead of more magical thinking, it’s time for the facts.

Let’s begin with Kansas, the most vivid example of an economic Petri dish for taxslashing trickle-down economics.

That’s the place where Gov. Sam Brownback persuaded his colleagues in the legislature in 2012 to slash income taxes drastically to deliver a “shot of adrenaline” to the state’s economy.

Funding for education, infrastructure and public services was dramatically reduced, the state’s bond rating sank and, instead of invigorating the economy, business growth lagged behind that of neighboring states. The state got sued for failing to provide adequate educational services to its children and lost in the Kansas Supreme Court.

Instead of producing tens of thousands of new jobs in Kansas, the tax cuts resulted in a decline in job growth and plunging state revenues.

By 2017, the Republican-controlled legislature did the unimaginable and voted to increase taxes in a frenzied attempt to keep the state budget afloat in the face of a $900 million budget gap. Then, when the thickheaded governor vetoed the tax increases, the legislature overrode him.

Tracy Gordon, senior fellow at the Tax Policy Center, said study after study finds that tax cuts have only the most tenuous relationship with economic growth, if any.

If it were that simple, Kansas would be booming and California, whose voters increased taxes in 2012 to boost funding for education and to help the state pay down its debt, would be in an economic slump. Quite the contrary, California’s economy has increased from a rate of growth of 2.6 percent in 2012 to 4.4 percent in 2015 and settling at 3.3 percent in 2016.

Here in Colorado, taxpayers have demonstrated what happens with what Gordon calls “ballot-box budgeting.”

The so-called Taxpayer’s Bill of Rights requires voter approval for tax increases. This means that problems that result from growth, economic downturns, natural disasters or the whole array of regularly-occurring factors called life cannot be addressed until they get severe enough to seize the attention of folks who have more pressing things to do than evaluate studentteacher ratios, calculate traffic volumes per mile or decide whether we have enough tanker planes to fight summer wildfires.

In other words, ballot-box budgeting by definition is behind the curve. It’s sluggishly reactive.

That’s how you end up with a crisis where teachers with advanced degrees can end up eligible for food stamps.

The question is, do Coloradans have the guts to change course? I mean before things start going all Kansas?

It will take leadership for sure and, Gordon said, a lot of public education.

When the economic downturn happened in 2008, states closed motor vehicle offices and reduced other services, Colorado Springs turned off streetlights and, not surprisingly, people noticed.

Now, across the country, Gordon said, governments are opening their books and creating data visualization platforms so people can see what they get for their tax money before the lights get turned off, the potholes take over and the schools are shuttered.

At the same time, a new generation is coming of age that has lost patience with the status quo and, not just incidentally, knows its way around an electronic database. Their indomitable attitude is being exhibited on the steps of state capitols and across social media this spring.

It’s inspiring to a lot of us, not just teachers.

So, maybe 40 years into the great taxcut experiment and the widespread evidence of its failure, they will finally come up with some solutions, not just

more excuses.

Diane Carman is a Denver communications consultant and a regular Denver Post columnist.