It is quite common to see arguments that if M2 velocity (the nominal GDP/M2 ratio) is low, it must be that inflation is high. While M2 velocity is currently at historical lows, inflation is clearly not high. Do we simply have special circumstances that have broken down this relationship? Is there such a relationship in the first place? Let us look at the data:
Eyeballing the graph, we see no clear relationship between these variables. There is a better alternative than line graphs to eyeball correlations, though: scatter plots. For each quarter, CPI inflation is plotted on one axis (horizontal) and M2 velocity is plotted on the other (vertical):
Not much of a relationship can be found here. If anything, there is a slight upward slope, indicating that higher M2 velocity is associated with higher inflation, although this would not be statistically significant.
How these graphs were created: Search for M2 velocity, then add CPI. Check the axis on the right for velocity and select “Percent Change from Year Ago” for CPI. This gives you the first graph. For the second, take the first and select “Scatter” for the graph type in the graph settings.
Suggested by Christian Zimmermann