What’s a diffusion index? If you don’t know, you’re not alone, but you’ll want to learn about this tool used for measuring employment and other economic changes. The general gist: A diffusion index is a way to determine the dominant trend of a group of statistics. If a greater number of stats are rising than are declining, the index will be above 50; if fewer are rising than declining, it will be below 50.

In Minnesota Economic Trends , Dave Senf takes a deeper dive into diffusion indexes, explaining how they are used to track employment trends, what Minnesota’s employment diffusion index looks like compared to the national index and whether diffusion index trends signal upcoming economic changes.