Economic Adjustment Module (EA). The third module incorporates a regional economic impact model to estimate total impacts on the economy of the study region(s). This includes impacts of: (a) direct business responses to changes in transportation conditions and factor costs, (b) indirect effects on suppliers due to inter-industry supplier-buyer linkages, (c) induced effects generated by the recirculation of added worker wages in the local economy, and (d) other dynamic adjustments in the economy over time.

The TREDIS-EA module aggregates direct impacts from the previous two modules to appropriate sectors, adjusts for double-counting, and formats the inputs based on the unique "policy-levers" of the economic model. In some cases, select direct travel impacts must be translated into direct economic impacts based on industry responses to competitive cost changes. These direct impacts are passed - along with project construction and O&M spending - to the economic model to determine regional increases in employment, output, and income.

Results. The economic adjustment module shows the effect of transportation projects, policies or programs on changes in employment, wage income, business output and GDP (value added). Impacts can be displayed as tables or graphs, with results disaggregated by year, by industry and by study area.

Regional Economic Model Options.  The modular aspect of TREDIS® allows it to be used with nearly any form of regional economic model. TREDIS is normally supplied with a CRIO (Cost-Response Input-Output) macroeconomic impact forecasting system, which incorporates the social accounting framework of the multi-regional IMPLAN® system, together with time-series forecasting and econometric equations for cost responses. IMPLAN works seamlessly within the TREDIS framework by agreement with MIG (the Minnesota Implan Group, Inc.).  It is available for any combination of counties or states in the US, and a special version is also available for provinces and regions in Canada.

TREDIS can also be used with REMI Policy Insight®, Global Insight, REDYN, RIMS-II, and other input-output models. Customized local input-output models and multiplier systems can be directly incorporated into broader the CRIO framework. Simulation models such as REMI work with TREDIS through an external adapter.

Note: TREDIS® is a registered trademark of Economic Development Research Group, Inc., IMPLAN® is a registered trademark of Minnesota Implan Group, Inc. Policy Insight® is a registered trademark of Regional Economic Models, Inc.