IMPLAN Pro: Aggregation Builder

Aggregation can be applied to the model in two different ways. You can aggregate the underlying Study Area industries prior to running impacts or create/select an aggregation template to apply to the results of the impact. Please note that the former may result in aggregation bias. In both cases you will need to create/select the aggregation scheme you want to apply to your model in the aggregation builder, found under the Options menu.

Importing an Aggregation Scheme

Aggregation schemes available for import are displayed in the Aggregation Library. If custom created aggregation schemes have been exported, these will also be included in this screen. Select an aggregation scheme to .

 creates 20 aggregated Sectors based on 2 digit NAICS Codes. The NAICS code for each Sector is listed with its description and is separate from its new IMPLAN code.

 aggregates the 536 Sectors to 86 Sectors based on 3 digit NAICS Codes. The NAICS codes are listed in the description.

When an aggregation scheme is imported, the aggregated sectors will appear in the User Defined Aggregation fields, and the Sectors field will display any un-aggregated Sectors. The IMPLAN Sectors incorporated in each aggregated Sector can be viewed by highlighting that Sector. 

IMPLAN models can be aggregated using custom schemes or imported schemes. It is important to remember that if you aggregate a model (as opposed to aggregating the impact results) the model cannot be unaggregated or re-aggregated. If you need to return to a disaggregated or an alternate aggregate scheme after aggregation has been applied, a new model will need to be created. Also, a model must be aggregated before impact Activities are created, as aggregating after creating the Activities may cause errors in impact calculations.

Applying the Custom Aggregation to Your Study Area Data & Results

When the desired aggregation model is selected and complete, you have two options. If you want to aggregate the background study area data, select . If you want to aggregate your results after you have run the model, the Aggregation Builder with the selected aggregation scheme in place. For additional information on how to apply your selected aggregation scheme to results, click here.

If you select , the Study Area information will be aggregated. Once this is finished, the model will indicate the process is complete.

Once a model has been aggregated, it must be reconstructed. This is indicated in both the Aggregation Complete screen and the progress bar.

IMPLAN models can be aggregated using custom schemes or imported schemes. It is important to remember that if you aggregate a model (as opposed to aggregating the impact results) the model cannot be unaggregated or re-aggregated. If you need to return to a disaggregated or an alternate aggregate scheme after aggregation has been applied, a new model will need to be created. Also, a model must be aggregated before impact Activities are created, as aggregating after creating the Activities may cause errors in impact calculations.

General Aggregation Builder Functions

Rename Sector

The  button can be used to edit or change the Sector name of user created or imported aggregated Sectors.

Edit the name as desired in the field and then click  to save changes.

Delete Sector

 removes the highlighted Aggregated Sector from the aggregation scheme.

 removes all custom or imported aggregated sectors.

Import Scheme

 imports the highlighted model in the Aggregation Library into the User Defined Aggregation Scheme. If a User Defined Aggregation Scheme already exists, or a previous scheme has been imported, a warning will appear.

 imports the selected scheme into the User Defined Aggregation Scheme field, deleting any custom created values or the previously imported scheme.

 returns to the main aggregation window.

Once the aggregation import is complete, the software will prompt:

 returns to the Aggregation Builder window, where you can browse the imported aggregation scheme, aggregate the model, or close the scheme for later use.

Export Scheme

 Exports custom created schemes to the library so they may be used in other models.

The name provided for the newly aggregated Sector should be easy to recognize. This will allow it to be easily located for import into future models. Type the name and click .

Once the software indicates that the export is complete, the sector can be viewed in the Aggregation Library and is available for import.

Delete Scheme

 discards aggregation schemes from the library of the current model.