Author Archives: Menzie Chinn

A Unit Root in a Bounded Series?

Commenting on the Kansas Palmer Drought Severity Index, Rick Stryker writes: “From a theoretical point of view it must be stationary.” He reasons that this is so, because it is bounded between -10 and +10. Question: Is this a relevant piece of information when examining finite samples? Let’s look at consumption as a share of GDP, which must be bounded between 0 and 1.

cons_gdp

Figure 1: Nominal consumption to GDP ratio, SAAR (blue). Source: BEA, author’s calculations.

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Three Trillion Dollars Spent in Iraq?

Long time readers of Econbrowser know that I have tabulating US direct outlays in Operation Iraqi Freedom, and operations thereafter. Imagine my surprise when in The Commander in Chief Forum, Donald J. Trump stated that we’d spent three trillion dollars. This prompted me to refer to actual, real-world, data. As far as I can tell, three trillion is not a number that exists in reality.

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