A Kerry ad again blames Bush for long-standing tax incentives for companies keeping capital overseas.

From www.factcheck.org

As we explained earlier, Kerry is referring to a feature of the US tax code that has been there since the corporate income tax was first adopted, through both Democratic and Republican administrations. Economists say it is a relatively minor factor in the decisions companies make to locate jobs overseas. Even Kerry admits his own tax-change proposal won't end the "outsourcing" of jobs overseas.