Unlike the Chicago Fed National Activity Index, the Lantern Daily Economic Index (LDEI) includes real and inflation data. This better reflects the “totality of the data”. The chart below shows how the LDEI compares to nominal GDP (QoQ%) over its history. They are very similar, but the LDEI provides about 60x times more fidelity (the number of business days in a quarter is about 65.)

The correlation coefficient is only +0.33 between them but the two have a much higher correlation of +0.61 with a 65-business day lead time (approx. 3-months.) In other words, the LDEI is a decent predictor of nominal GDP 3-months ahead of it. It is far from perfect, and it would be foolish to use this to predict GDP. The Atlanta Fed’s GDPNow is better for that purpose. The LDEI is more about the Fed and interest rates.

But in general, the regression suggests that ((LDEI level * 1.84%) + 4.78%) = nominal GDP. Stated another way, a zero-level of the index suggests a 4.78% nominal GDP. With the GDP deflator (inflation) at 1.9% in the latest quarter, this further suggests a real GDP level of 2.9% when the index is at 0. This will change as inflation changes. With the index currently at +0.161, it implies an instantaneous real GDP rough estimate of 3.2%; but not a prediction of Q4 GDP.

These are some broad rules of thumb about what the index level means.