Consideration was paid to the potential of double‐counting activities between supplier,
dealership and assembler runs. Within the framework of the REMI model, there is an interindustry,
input‐output (I‐O) table that calculates demand for intermediate inputs used in the
production of a finished good. A more rigorous effort to avoid double‐counting was applied to
this study versus the 2010 study. In this study, all automaker employees who manufacture parts
were not included as direct employees in the assembler simulation. Next, common to both
studies, the automaker simulation model was run first, then the calculated demand for parts
suppliers associated with automakers were discounted (these are the suppliers who will be
included as direct employees of parts manufacturers in the second run). With both types of
parts makers (those employed by automakers and those employed by Tier 1 parts suppliers)
removed from the assemblers simulation, the CAR research team was able to adjust for
systemic double counts and calculate only the net employment effects for the assembler
simulation runs.
As a consequence of this up‐front effort to avoid double counting between segments of the
industry (automakers, parts suppliers and dealerships), the results for each of these segments
can be added together to arrive at the total economic contribution of the industry. These
results fairly represent the size of the industry and its contribution to the U.S. and individual
state economies. All simulation results are relevant to the economic conditions of calendar year
2014.