Figure11-4Average and Marginal Product of Labour Curve for Alec and Janet’s Farm The table shows the production function, the relationship between the quantity of the variable input (labour, measured in number of workers) and the quantity of output (wheat, measured in bushels) for a given quantity of the fixed input and the productive technology. It also calculates the average product of labour on Alec and Janet’s farm. The average product of labour curve shows the average amount of output produced per unit of labour, for a given amount of workers employed. When the farm has 1 worker, its average product is 19 (the same as the total product). When the farm employs 2 workers each worker, on average, produces 18 bushels, and so on. The curve slopes downward due to diminishing returns to labour.