MSNBC is reporting that General Motors (GM) plans to close “most” of its U.S. factories for up to nine weeks this summer, due to its swiftly growing collection of financial problems:

Two people briefed on the plan say General Motors Corp. will close most of its U.S. factories for up to nine weeks this summer because of slumping sales and growing inventories of unsold vehicles. The people did not know exactly when the shutdowns would occur, but both say they will include the normal two-week closure in July to change from one model year to the next.

But just yesterday, the Associated Press reported that GM spent $2.8 million lobbying Congress — nearly $1 million per month — in the first quarter of 2009, which is actually 15 percent less than it spent on lobbying in the final quarter of 2008. GM also said this week that “it is completing the layoff of 3,400 white-collar workers in the U.S.”

“We’re a part of what is arguably one of the most regulated industries and provide a voice in complex policy discussions. We meet strict reporting requirements and our spending is reflective of the breadth of issues that affect our business,” said GM spokesman Greg Martin. But it’s worth asking: How many days could GM keep some factories open with that money? How many workers could have earned just a little bit more in wages if that lobbying hadn’t occurred?

As we’ve noted before, the business lobby has gone into high gear to defeat the Obama administration’s proposal to stop allowing corporations to defer taxation on profits they make overseas. “This one hits the bottom line of companies more than any other issue right now. We have to defeat it,” said Ralph Hellmann, the lead lobbyist for the Information Technology Industry Council.

With that in mind, it’s worth looking at how corporations use this deferral to avoid paying taxes. And courtesy of the Wall Street Journal, we have the amount by which some corporations lowered their effective tax rate in 2008 thanks to the current law:

Remember, the statutory rate that the right-wing is always up-in-arms about — but which few corporations actually pay — is 35 percent. But General Electric was actually able to lower its effective rate all the way down to 5.5 percent, due to its use of deferrals, tax havens, and other intricacies of the corporate tax code.

According to a report from the U.S. PIRG Education Fund, a $100 billion annual tax burden is shifted to US-based individuals and companies thanks to corporations stowing their profits offshore:

Over ten years, an estimated $1 trillion in revenues is lost due to the use of tax havens and the government must make up for this shortfall. This diversion ends up being shouldered by other companies and taxpayers and is transferred as higher debt for future generations. The recent Senate Budget resolution concluded that the problem of offshore tax havens “means that honest taxpayers face a higher burden.”

And the Oxford University Centre for Business Taxation has found that corporations allowed to defer taxation on offshore profits will leave that money offshore regardless of their home nation’s tax rate. Indeed, when given the opportunity to bring this money back to America at a lower tax rate in 2004, corporations used most of the money “to buy back stock from shareholders, not to invest in domestic operations.”