theorem effectiveSectorMultiplier_nonneg (e : NSectorEconomy N) (n : Fin N) :
0 ≤ effectiveSectorMultiplier e n := by
unfold effectiveSectorMultiplier
exact mul_nonneg (sectorEffectiveCurvature_nonneg e n) (le_of_lt (e.hd n))Multiplier-Cycle Duality in a Multi-Sector Economy