Humans can lie strategically in order to leverage on their negotiation power. For instance, governments can claim that a "scapegoat" third party is responsible for reforms that impose higher costs on citizens, in order to make the pill sweeter. This paper analyzes such communication strategy within a variant of the ultimatum game. The first player gets an endowment, and the second player can impose a tax on it. The former can reject the allocation submitted by the tax-setter. A third party is then allowed to levy its own tax, and its intake is private information to the tax-setter. In a frameless experiment, 65% of the subjects in the tax-setter role overstate the tax levied by the third party in order to manipulate taxpayer's expectations and submit less advantageous offers; on average, for every additional currency unit of lie, measured by the gap between the claimed and the actual tax, they would reduce their offer by 0.43 currency units.
