Missouri voters are being asked to approve a constitutional amendment, submitted by Ameristar Casinos executive Troy Stremming, which would make a couple of significant changes in how business is done in Show-Me State casinos. (The full version is here, but the précis tells you what you most need to know.)

There are three salient features to this amendment, which might be summarized as The Good, The Bad and The Neutral.

The Neutral: Taxes on casinos would be raised 1%, for a total rate of 21%. In and of itself, this is not such a big deal, as I'll explain below.

The Good: The amendment repeals the state's loss limits, a paternalistic measure which doesn't actually limit how much you can lose (like that's any of Jefferson City's beeswax) but how frequently you can buy in. This should have been history a long time ago or, better yet, never enacted.

The Bad: The amendment would close Missouri to new casino licensees. Anybody already licensed or building in Missouri (read: Pinnacle Entertainment) would be grandfathered. After passage of the amendment, the only way into Missouri would be if an existing riverboat were sold, went out of business or lost its license.

That's a pretty sweet deal, especially if you're Ameristar and probably want to bat your eyelashes at potential suitors. Ameristar's two Missouri casinos did a combined $160 million in cash flow last year and the company, using its 2007 financials, is conservatively worth $2.1 billion. A freezing of the Missouri market would make Ameristar more valuable still.

But the amendment anti-competitive on its face. Nor have I heard any compelling argument for closing Missouri to additional operators -- other than protecting the ones already there from an environment that will be somewhat more competitive as Kansas' casinos begin to enter the fray.

And ... this may be more cracker-barrel philosophy than economic theory, but if Ameristar, Pinnacle, et. al. are going to enjoy protected-oligarchy status, the citizens of Missouri ought to get more than an extra percentage point of tax from those sinecures. If voters are being asked to slam the door in the face of prospective casino developers (such as one in Cape Girardeau), then existing operators ought to reciprocate by agreeing to a new tax rate that's not one but several points greater.

As it stands, the best-case estimate is that the 1% increase will bring an extra $156 million per year to state and local kitties. Ameristar's riverboats alone represented $117 million in gaming-tax revenues last year. Missourians will have to weigh the $156 million bird in the hand against the bird-in-the-bush economic impact that one or more additional casinos would represent. For once, I'd take the bird in the bush.

Correction: Yesterday, I passed along a Center for Responsive Politics assertion that presidential campaign donations from the defense industry favored Sen. John McCain. According to OpenSecrets.org, it's the other way around and they've got the numbers to back it up. (It seems to have more to do with longstanding resentment of McCain among defense contractors than with enthusiasm for his opponent.)