 No individual has an incentive to misrepresent his or her true values under the Groves-Clarke mechanism. Suppose we change the valuations in the above example so that the public good is now worth −24 to Bob (by adjusting his reservation price to 51). It should still be produced as the sum of valuations remains positive (alternatively, the sum of Bob’s and Sally’s reservation prices remains above the cost of producing the public good). Bob does not have an incentive to misrepresent his valuation (by bidding below −24) because with the transfer of 25 he receives he is still better off than if the public good was not produced. The same is true of Sally. She’ll have to pay a tax of 24 but is still better off than if the public good was not produced. If we lower Bob’s reservation price further to below −25, he would be worse off despite the transfer and thus accurately bid the true, low value. Sally, even though she would prefer the public good to be produced in the absence of transfers would also be worse off after paying the tax and therefore has no incentive to overstate her valuation.