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.
According to Jim sense for us". But on June 27, 2007, ABC renewed the show for a seventh season with 18 episodes. "According to Jim" returned to ABC's schedule on Tuesday January 1, 2008, with two episodes at 9 pm and 9:30 pm. After that, the series moved to its regular time slot at 8 pm. Despite the writer's strike, ABC announced that the show would produce all 18 episodes ordered for this season. On February 27, 2008, it was reported that ABC was close to renewing "According to Jim" for an eighth season. On May 13, 2008, ABC officially renewed the series