I thought of an easier way to do the "real" calculation for data that accumulates over multiple years. Debt is the obvious example of something that accumulates over multiple years.
Here's the calculation:
Take the change in debt as a share of nominal GDP, multiply it by the real GDP value for that period, and add the previous period's Real Debt value. That's it. That's the whole calculation....The New Arthurian Economics
A new "real debt" calculation