brief introduction: I have become more and more accustomed to translate observations about the competitive strategy as well as the general demand/supply/new trends of the underlying industry into both accounting assumptions (revenue/COGS/D&A/Capex/etc) and valuation matters (risk/multiple analysis/reasonable LT growth rate/etc) but I am still failing to put the macroeconomic input in the midst.
example: I am trying to put into perspective the taxi market (Uber environment) and trying to gauge market share as well as the kind of contracts Uber can negotiate relative to the frequency users switch from normal taxis. good. i can read reports and market studies for this but they are inherently using some macroeconomic assumptions (GDP per capita/employment/trade balances/inflation/etc) that directly affect the number of total passengers (more unemployed means less business people getting into taxis).
what way (preferably rigorous & testable) would you devise to plug into the model such macro assumptions that do change the industry landscape? (=report says 30 mil passengers in US with CAGR 5% but I think workforce will shrink so how i do translate such estimate into changing those sensitive numbers)