Recent microeconometric studies of taxpayers’ responsiveness to taxation have shown that intensive margin labor supply and earnings elasticities typically are modest and sometimes equal to zero. However, a common view is that long-run responses might still be large since micro-estimates are downward biased owing to optimization frictions. In this paper we estimate the taxable income elasticity at a very large kink point of the Swedish tax schedule using the bunching method. During the period of study the change in the log net-of-tax rate reached a maximum value of 45.6%. Interestingly, we obtain a precise elasticity estimate of zero for wage earners at this large kink. The size of the kink allows us to derive tighter bounds on the long-run elasticity than previous studies. If wage earners on average tolerate 1% of their disposable income in optimization costs, the upper bound on the long-run taxable income elasticity is 0.39. We also evaluate the performance of the bunching estimator by performing Monte Carlo simulations.