cutting those $100 of labor leaves you with $140 in 30% scenario vs. $160 in 20% case. The similar goes for capital investments with associated depreciation. This is why tax cuts is the time to take money out of business through dividends, buybacks, etc. and not the time to expand the business (i.e. not the time for additional employees and capital investment). It does put comparatively higher pressure to increase productivity using existing employees on/in existing machinery/buildings/etc.