In a violation of the 8th Amendment’s prohibition against cruel and unusual punishment, my brutal overseers at the Cato Institute required me to watch last night’s debate (you can see what Cato scholars said by clicking here).

But I will admit that it was good to see Obama finally put on the defensive, something that almost never happens since the press protects him (with one key exception, as shown in this cartoon).

This doesn’t mean I like Romney, who would probably be another Bush if he got to the White House.

On the specifics, I obviously didn’t like Obama’s predictable push for class warfare tax policy, but I’ve addressed that issue often enough that I don’t have anything new to add.

I was irked, though, by Obama’s illiteracy on the matter of business deductions for corporate jets, oil companies, and firms that “ship jobs overseas.”

Let’s start by reiterating what I wrote last year about how to define corporate income: At the risk of stating the obvious, profit is total revenues minus total costs. Unfortunately, that’s not how the corporate tax system works.

Sometimes the government allows a company to have special tax breaks that reduce tax liabilities (such as the ethanol credit) and sometimes the government makes a company overstate its profits by not allowing it to fully deduct costs.

During the debate, Obama was endorsing policies that would prevent companies from doing the latter.

The irreplaceable Tim Carney explains in today’s Washington Examiner. Let’s start with what he wrote about oil companies.

…the “oil subsidies” Obama points to are broad-based tax deductions that oil companies also happen to get. I wrote last year about Democratic rhetoric on this issue: “tax provisions that treat oil companies like other companies become a ‘giveaway,’…”

I thought Romney’s response about corrupt Solyndra-type preferences was quite strong.

Here’s what Tim wrote about corporate jets.

…there’s no big giveaway to corporate jets. Instead, some jets are depreciated over five years and others are depreciated over seven years. I explained it last year. When it comes to actual corporate welfare for corporate jets, the Obama administration wants to ramp it up — his Export-Import Bank chief has explicitly stated he wants to subsidize more corporate-jet sales.

By the way, depreciation is a penalty against companies, not a preference, since it means they can’t fully deduct costs in the year they are incurred.

On another matter, kudos to Tim for mentioning corrupt Export-Import Bank subsidies. Too bad Romney, like Obama, isn’t on the right side of that issue.

And here’s what Tim wrote about “shipping jobs overseas.”

Obama rolled out the canard about tax breaks for “companies that ship jobs overseas.” Romney was right to fire back that this tax break doesn’t exist. Instead, all ordinary business expenses are deductible — that is, you are only taxed on profits, which are revenues minus expenses.

Tim’s actually too generous in his analysis of this issue, which deals with Obama’s proposal to end “deferral.” I explain in this post how the President’s policy would undermine the ability of American companies to earn market share when competing abroad - and how this would harm American exports and reduce American jobs.

To close on a broader point, I’ve written before about the principles of tax reform and explained that it’s important to have a low tax rate.

But I’ve also noted that it’s equally important to have a non-distortionary tax code so that taxpayers aren’t lured into making economically inefficient choices solely for tax reasons.

That’s why there shouldn’t be double taxation of income that is saved and invested, and it’s also why there shouldn’t be loopholes that favor some forms of economic activity.

Too bad the folks in government have such a hard time even measuring what’s a loophole and what isn’t.