There's a lot of talk these days about inflation and the impact of Fed policy on the dollar and the extension through the weaker dollar into higher commodity prices. Those looking to flame the Fed for its quantitative easing (QE) and generally loose monetary policy point to the falling dollar as the cause for oil going up above $100 and gold crossing $1500. While it's certainly true that the greenback is lower (the USD Index has been as much as about 12% off it's January peak), is the weak dollar really to blame for things like the rising cost of gasoline at the pump? Let's take a look at what the charts have to say about it all.
First is a comparative chart of oil prices in dollars and oil priced in euros. The chart below covers the last year's trading. The red line is the dollar value of a barrel of oil, referencing the left scale. The black line is the euro price of a barrel off oil (using front month futures), with that price on the right scale. Both scales are logarithmic so they express similar percentage moves between noted levels.
Now, the chart above doesn't show relative % gains for oil in the two currencies. Those are +31.3% in USD terms and +22.6% in EUR terms. This is about what we'd expected given the relative performance of EUR/USD over that time. The point of the chart is that aside from wiggles where oil has done better in one currency than the other for a period of time, the pattern of the two lines is consistent. Oil has been moving higher in roughly the same pattern, regardless of what currency we're talking about.
Now let's take a look at gold (again front month futures). Once more, the red line is in dollar terms and references the left scale, and the black line is euro terms referencing the right scale.
In this case, gold is up 29.6% against the USD and 19.4% in EUR terms. Again, that difference can be explained by the change in EUR/USD over the last year, which is as it should be. Here, though, we see a lot more variation in performance. In dollar terms gold has been in a fairly steady uptrend with only two relatively minor retracements. In euro terms, however, the ride has been much more dramatic. Those periods when the EUR line diverges considerably from the USD line are periods when EUR/USD was selling off.
The chart below highlights the variation between how gold and oil trade relative to the dollar. It shows EUR/USD on the top with the correlation between EUR/USD and gold plotted in red and the one with oil plotted in green.
Notice how much choppier the green line is than the red. That means the correlation between oil and EUR/USD is much more fickle than the one between EUR/USD and gold. That said, however, oil has spent more time with a positive correlation (meaning rising oil with rising EUR/USD and falling oil with falling EUR/USD). The gold correlation has been much more balanced. In particular, the gold correlation has been more negative when EUR/USD is falling.
Now, correlation does not mean causality. It just shows how similar the movement patterns are without looking at why that might be. The way I would tend to read the above, however, is to say that rising gold is more a factor of what's happening in the currency arena than rising oil prices. If you think about the implications of increasing money supply (which is what loose monetary policy is), then it makes sense. Gold is something with what could essentially be called a near fixed supply (very slowly increasing), so the more dollars there are the higher the value of gold per dollar (or any other currency). Oil has a different dynamic which is must more closely tied to economic considerations and geopolitics.