Combining Regions in IMPLAN allows you to create Regions of grouped geographies to analyze. The great part is once you create a Combined Region, it will always be available for you to use. This is the easiest method when you have only a few areas to combine. If you have a lot of Regions you want to combine, we recommend using the Region List.
You can create a custom Combined Region in IMPLAN with just a few simple clicks. From the Regions screen, select all of the Regions you want to combine. Click the Menu Button in the Selected Regions field.
A popup will appear asking you to name your new Combined Region. Remember to give it a name that makes sense as this will now be searchable in from your Regions or Impacts screen.
IMPLAN is now building your Combined Region. You will know it is complete when the teal icon appears next to the Region Details as shown below.
You can now proceed with your analysis by clicking Create Impact in the bottom right corner of your screen.
If you have a lot of Regions to combine, like the 87 counties in Ohio besides Cuyahoga, you can also combine Regions using the Region List which is a much faster option.
You can always start a new Project using this Combined Region by searching for the title you gave it on the Regions screen.
Note that there is a limit of 200 geographies in Combined Regions.
Combining Regions is very useful when you are using MRIO. For example, you may want to compare your county to the remainder of the state. To ensure that your Project runs efficiently, you can create a Combined Region for all of the other counties in your state. You can then MRIO your county to the Combined Region of the remaining counties. So instead of having to use MRIO with Cuyahoga County, OH and the other 87 counties, you can use MRIO with Cuyahoga County and a Combined Region of the 87 Ohio counties.
Written April 24, 2020
Updated September 22, 2021