How Did NPR Determine that the Political Deadlock Is Slowing the Economy?

Cokie Roberts told listeners that the political deadlock between President Obama and Congress is slowing the economy [sorry, no link yet]. It is far from clear that this is the case. Consumption as a share of disposable income is actually higher than its post-war average. Investment in equipment and software is nearly back to its pre-recession share of output, which is striking given the large amount of excess capacity in most sectors of the economy. It is not clear what component of GDP that...