I have a large dataset where I have summed point values in polygons. I have a separate value per year, over five years. I want to find the trend in each polygon over time. I'd like to set up a regression to find the coefficient for change (positive or negative trend) in each polygon, but can't figure out how to set this up. Any suggestions? Thanks!

Alison, you can run the expression I provided in the field calculator. I am also going to suggest that you look at grouping analysis as a way of characterizing how the polygons are changing over time: Grouping Analysis—Help | ArcGIS for Desktop