IMPLAN multipliers are used in "input-output" models where a dollar
spent in a particular sector within a state, region, or county (in this case,
construction) is expected to impact a host of local industries, from local
restaurants to feed workers to gas stations needing to transport
workers/materials to concrete suppliers, etc. The multipliers suggest that
spending from construction will in turn create so many "direct" and
"indirect" jobs for cooks, food servers, gas station attendants,
cashiers at the lumber yard, truck drivers to deliver materials, etc. My biggest concern with preservation of old buildings is their operational
costs and energy efficiency. Often, to retrofit such buildings to be more
energy efficient can conflict with preservation boards (no solar panels on
historic buildings or no added insulation as it will impact the walls), so
you're left with big energy guzzlers for owners (often which are cities and
towns where tax payers foot the power bills).
These studies stretch realities and are manipulated to come up with preconceived
conclusions. The sad part is that they are published in newspapers without any
real challenge to the manipulated information in the study.