Where your impact is taking place is a pretty easy question to answer. However, you may want to talk about that impact at the local, regional, or state level as well. You may even want to look at how an Event in one Region impacts another Region.
The Region you define determines the boundary for which estimated spending is captured as an effect to the Region. The spending that does not affect the Region you’ve defined (according to the model) are called leakages.
GEOGRAPHY LEVELS IN IMPLAN:
Regions can be accessed by clicking Regions via the IMPLAN Dashboard at app.implan.com. Once a Region has been built, it can also be selected via the Region field of a Group in the Impact Screen. Data about a Region can be accessed “behind the i” in the Regions screen once a Region is selected and built.
From the Regions screen, you can select a Region by typing the name of one of the following US geography levels in the Search field:
- ZIP Codes
- Congressional Districts
- Country (United States)
You can also select States and Counties by clicking on them on the map. Toggle the map between State View and County View by using the map view dropdown at the bottom right-hand corner of the map shown below.
Single & Combined Regions
You may want to look at a change in your county and how that affects your county. Pretty straightforward. In IMPLAN you can also combine smaller geographies to create a custom region. To do this, navigate to your Regions screen and click on or type in the names of all of the geographies you want to combine into one new combined region.
Next, click on the Advanced Options in the upper right corner of your screen just above your first listed Region.
A new box will pop up prompting you to give your combined region a name. If you want to use this same combination in the future, give it a logical name that you will remember as IMPLAN will save all of your combined regions for you.
Click SAVE and IMPLAN will start building your new combined Region for you. When the teal icon shown below appears, your new Region has been built and you are ready to input your Events.
Be aware of aggregation bias – which stems from the loss of detail that occurs when you combine regions together to form a blended larger region.
In addition to defining your analysis Region based on where the impact is taking place and where you want to measure the effect, it's also important to consider the functional economy. A functional economy encompasses the major labor and production shed of the impact or contribution being modeled. This means that the region captures the local supply chain and areas in which employees are living and spending their income.
A functional economy has established economic networks and can support demand for labor as well as goods and services needed by both households and businesses. How long spending will circulate within an economy depends on the functionality of the economy. This is because there will be less leakage of spending in a more functional economy, relatively. Leakages of spending into other Regions occurs primarily due to imports of goods and services into your Region as well as non-resident employees (in-commuters) working in your Region. IMPLAN estimates these leakages for you based on your defined Region. You can adjust your commuting rate if you know specific information that you would like to model.
ZIP Code Regions
A single ZIP code can rarely be considered a functional economy, but combining ZIP codes to build a particular Region is a great way to create a functional economy with a custom geographic boundary.
It should be noted, our data sources are more robust at the county geographic level and higher. Not only is there a higher probability of non-disclosure with the data at the ZIP code level, there also is a significantly less amount of raw data available in general at the ZIP code level. The main justification for using the ZIP code level data would be if a county is large and very different in different parts of it - for example, a mostly rural county that happens to have one large city within it, in which case the county as a whole is not a good representation of its distinct regions. If the user has good data with which they could customize the Event or use ABP, we'd still recommend the county region in that case!
Comparing & Contrasting
IMPLAN does have the ability to show you how the Event might look different if it were in Indiana or in Illinois. You can create one Event on your Impacts screen and drop it into both counties. Then on the Results screen, use your Filter to flip between the two geographies to see the differences.
Results Across Geographies
You may want to look at how your event in Mecklenburg County, NC, but also how it will affect nearby Gaston County. This can be done using a feature in IMPLAN called Multi-Regional Input-Output Analysis (MRIO) which links Regions together. Remember, different stakeholders may be interested in the results at different geographies. MRIO will estimate the interregional linkages of trade and commuting effects across these different geographies.
Written December 10, 2019