| Term | Definition |
| constant returns to scale | If the use of all inputs increases by k per cent, output also increases by k per cent. Long-run average cost is constant with respect to changes in output. |
| increasing returns to scale or economies of scale | If the use of all inputs increases by k per cent, output increases by more than k per cent. Long-run average cost is decreasing with respect to an increase in output. |
| breakeven | It is the point at which cost or expenses and income are equal - there is no net loss or gain |
| marginal product of labor | the additional output as a result of increasing the labor input by one unit |