UPDATED AT 1:59 PM MONDAY: If you came away from all the talk last week about an "economic growth" package not knowing how the measures under discussion might actually affect your business, don't feel bad. Neither, apparently, did the officials who hammered out the agreement.

It took an inordinate amount of effort (by which I mean it wasn't within easy reach of the Google News homepage) for your intrepid reporter just to learn that the business stimuli enhance two tax deductions for new investment, a bonus depreciation for capital expenditures and a generous deduction for other small business expenses. But once I found my way to the web pages of the principal architects -- the White House, House Speaker Nancy Pelosi, and House Minority Leader John Boehner -- I understood why: their statements were at odds over the write-offs' specifics.

For instance, the bonus depreciation will benefit all businesses by allowing them bigger deductions in 2008 for plant or equipment purchased this year -- but it's not clear how much bigger. According to Pelosi's office, "firms can write off 50 percent for investments in 2008," while the White House says that companies will be able to "deduct an additional 50 percent of the cost of their investment in 2008" (my emphasis) -- suggesting a big write-off on top what a company can already take. (For equipment depreciated over seven years, that's typically between 14 and 25 percent of the cost, according to Anita Mandelbaum, a CPA who happens to be my mother.) A significant difference, no?

Likewise, the incentive for small firms temporarily rewrites Section 179 of the Internal Revenue Code, which allows them to take large first-year deductions on certain expenses, often providing a full write-off immediately. "The bipartisan plan," trumpets the Speaker, "doubles the amount small businesses can write off their taxes for new investments made in 2008 from $125,000 to $250,000'¦" So far, so good. But then it becomes incomprehensible (and I haven't changed a word): "'¦and increase the number of small business that are eligible for this tax relief for small business making up to $800,000 (from $500,000)." This second part makes no sense, and not just because it's barely coherent--Section 179 doesn't specify any limits on business income. The rule does, however, limit the investment qualifying for the preference to $500,000.* Which is why I put more faith in the statement from Republican John Boehner's office. It also specifies a higher $250,000 deduction in 2008 for "both new and used tangible property" purchased this year, but "up to an overall investment limit of $750,000." (Interestingly, the White House had no specifics on the Section 179 proposal, which may say something about the priority the Bush Administration places on its entrepreneurial constituency.)

So who's right? The Republicans are, even though most of the (few) press accounts I've seen that reported the details appeared to rely on the Pelosi statement.** (That includes, for one, the front-page story in the New York Times.) Just after I originally posted this, a spokesman for Majority Leader Pelosi wrote to say, "There are no disagreements between the parties. There have been clerical errors in some of our materials as they went out very quickly, and we are working to address those."

Perhaps this confusion explains a curious element in the small business stimulus legislation that John Kerry introduced last week in the Senate shortly after the Bush-House compromise was announced. The Kerry proposal would raise the Section 179 deduction from $125,000 to just $200,000, lower than the provision in the compromise. (Kerry's bill would allow more businesses to participate by raising the total investment limit to $800,000.) One wonders if he had trouble prying the details of the agreement from his colleagues in the House, or if he simply couldn't wait for them to figure out what they had agreed to. That's a question the Senate Small Business Committee didn't want to tackle today, but a spokesperson allowed that "Sen. Kerry put forward what he thought was a reasonable proposal and what he thought could get done for small businesses," and that he supports the more generous House measure.

Of course, Kerry isn't the only senator with his own ideas, and immediately there were rumbles that the upper house would bring its own wisdom to bear on jump-starting the economy. ("The Senate will want to speak as well," Senate Finance Committee Chairman Max Baucus told the Washington Post.) When -- if -- the package finally passes, it may be along the lines of Kerry's more modest proposal. Or it may be something completely different.

UPDATE, 2:49 PM ET THURSDAY: Putting my faith in the Republicans -- d'oh! Though Boehner's office got the nature of the expensing provision right, it got the number wrong. (And never returned my calls seeking comment.) The stimulus bill, which passed the House overwhelmingly on Tuesday, raised the cap on expenses that qualify for accelerated depreciation under Internal Revenue Code Section 179 to $800,000, not $750,000. Meanwhile, I see that Pelosi's office has corrected the mistakes in her online statement.


*Under the current rule, the special deduction allowed under Section 179 begins to evaporate dollar for dollar as the investment exceeds $500,000. The special deduction falls to zero once a company spends $625,000, and the firm must use the regular depreciation schedules. This effectively limits the provision to small firms.

**The fact that news accounts had so little to say about the business stimuli may reveal something about the priority the press places on its entrepreneurial readers.