Laffer curve is simplistic in that it assumes a single tax rate and a single labor supply. Actual systems of public finance are more complex, and there is serious doubt about the relevance of considering a single marginal tax rate. In addition, revenue may well be a multivalued function of tax rate; for instance, an increase in tax rate to a certain percentage may not result in the same revenue as a decrease in tax rate to the same percentage (a kind of hysteresis). Furthermore, the Laffer curve does not take explicitly into account the nature of the tax avoidance taking place.
Notional profit Notional profit Notional Profit A contract usually takes several years to get itself completed. If the profit on such contracts is recorded only after their completion, then wide fluctuations may be noted in the profit figures of contractors from year to year. To avoid these fluctuations in the reported profits and to reflect the revenue in the accounting period during which the activity is undertaken, the profit in respect of each contract in progress is transferred to the profit and loss account of the year by calculating the notional profit. The portion of notional profit to be transferred to the