When both supply and demand shift, the final step is to combine the two four-step analyses. Graphically, the two diagrams are superimposed. E₁ is the equilibrium after the supply shift alone, E₂ after the demand shift alone, and E₃ after both.
Effect on quantity. Higher labor compensation decreases the equilibrium quantity, and the change in tastes away from mail decreases it too. Both shifts are to the left, so the overall effect is a decrease: Q₃ is to the left of Q₀.
Effect on price. Higher labor compensation raises the equilibrium price; the change in tastes lowers it. The two effects work in opposite directions, so without knowing their magnitudes the overall effect on price is unclear. That is not unusual: when both curves shift, we can usually determine the overall effect on price or on quantity, but not on both. Move the sliders to see which shift wins.