Here at the FRED Blog, we celebrate every 100th post with a nod to that number. Today is our 800th, which turned out to be a challenge. We searched for “800” on FRED and found exactly one hit, which needs some explanation.

The FRED graph above shows data for the “800 concerns”: These “concerns” were a group of manufacturing businesses that varied in number from 261 to 793, yet somehow became known as the 800. The data come from the NBER Macrohistory Database, a patchwork of economic indicators that were collected for no more than a few decades, often by the NBER itself. This particular series was assembled and published by Geoffrey Moore for the NBER.

These data depict a diffusion index, which is a form of survey that asks a group whether something is going to increase, stay the same, or decrease. In this case, these manufacturing concerns were asked about their sales, specifically the change in sales compared with four quarters ago.

When the group, overall, expects conditions to stay the same, the diffusion index is at 50%. Higher values indicate more increases, and lower values indicate more decreases. This index shows continuous optimism among the manufacturers: Even during the two short recessions of the 1950s and the Korean War, more manufacturers saw sales increases than decreases.

These diffusion indexes are precursors to much more comprehensive business surveys that would later be conducted by various federal agencies. Many are available in FRED. The “800 concerns” was collected for less than a decade, with obvious interruptions.

How this graph was created: Search FRED for “800.”

Suggested by Christian Zimmermann.