The weekly demand for intercity bus journeys is expected to decrease from 25,000 to 21,000 bookings when the average household income in the region rises from £32,000 to £36,000 per annum.
What is the income elasticity of demand (YED) for this service?
−1.28-1.28−1.28
−0.78-0.78−0.78
+1.28+1.28+1.28
+0.78+0.78+0.78