My 7-year-old son knows better than to believe in the Tooth Fairy, but he was happy to act as if he did in order to cash in when he lost three teeth this month. He played his part convincingly, even slipping a note under his pillow asking if he could keep one of the teeth and still get paid for it. (“Dear Micah,” said the note he found the next morning, “My name is Tooth Fairy because I keep the tooth. But I will make an exception this time …”)

As I listen to the usual suspects braying for the defeat of Question 3, the Massachusetts ballot initiative to roll back the state sales tax from 6.25 percent to 3 percent, it occurs to me that they aren’t so different from Micah. They’re too bright to actually believe in the Tax Cut Monster — a mythical fiend who punishes any drop in tax rates by ravaging police and fire departments, throwing the sick and poor into the street, and reducing public infrastructure to rubble — but they act as if they do in order to keep cashing in on the backs of Massachusetts taxpayers.

So they howl that voting yes on Question 3 would be a “calamity” and a “complete disaster.” That it would “devastate state services” and impoverish local communities. And that the “dire consequences” of such a “draconian cut” will send Massachusetts “heading over the cliff.”

It’s an old routine. Remember how the blood was going to run in the streets if Proposition 21/2 passed in 1980? Remember how the Dukakis surtax was all that stood between civilization and apocalypse? But there was no blood and no apocalypse. Tax Cut Monster isn’t real.

“Unions have poured another $2 million into the fight against” Question 3, the Associated Press reported last week. To date more than $4 million has been spent on the effort to keep the sales tax from being rolled back, while Question 3’s backers have spent less than one-tenth that amount.

Public-sector unions, whose influence is directly linked to the size of government budgets, are hell-bent on stopping Massachusetts taxpayers from lowering what is now one of the highest sales-tax rates in the country. They and their allies will pull out all the stops to convince you to vote no. Here are four reasons to vote yes.

1. Because when times are tough, even state government should learn to make do with less. The limping economy has forced tens of millions of Americans to swallow hard and figure out how to live with diminished salaries, mandatory furloughs, and reduced benefits. Many of us have given up things we’d rather have because we just can’t afford them now. Taxpayers have had to get used to making do with less. The tax-eaters should have to as well.

2. Because the government’s budgets are as high as they’ve ever been. While Governor Deval Patrick claims to have “taken $4.3 billion out of state spending” and the so-called Massachusetts Taxpayers Foundation laments that “state programs have already been cut by more than $2 billion,” the bottom line is plain: Total state expenditures have climbed from about $22 billion in 2005 to $27.6 billion for 2011.

3. Because a lower tax rate will generate economic growth. An analysis by the Beacon Hill Institute at Suffolk University shows that a rollback to 3 percent “would create 27,199 private-sector jobs, increase annual investment by $73 million, and raise wages by $1.03 billion.” Money not confiscated by the public sector would remain in the far more productive private sector, while a sales-tax reduction would give Massachusetts businesses a competitive advantage. And any government jobs eliminated would be more than offset by the creation of new jobs in the private economy.

4. Because voting for Question 3 is the only way for Massachusetts taxpayers to get Beacon Hill’s attention. Two years ago the state’s voters defeated a ballot initiative to eliminate the Massachusetts income tax; the Legislature took that as an invitation to raise taxes even higher. Result: higher sales taxes and meals taxes, and new taxes on alcohol and satellite TV bills.

A vote for Question 3 is a vote to grab state government by the collar and give it a shaking it can’t ignore. Pass up this chance, and you may not get another.

© Copyright 2010 Globe Newspaper Company.