Lobbying when the decisionmaker can acquire independent information

Politicians trade off the cost of acquiring and processing information against the benefit of being re-elected. Lobbyists may possess private information upon which politicians would like to rely without the effort of verification. If the politician does not try to verify, however, the lobbyist has no incentive to be truthful. This is modelled as a game in which the lobbyist lobbies to show his conviction that the electorate is on his side. In equilibrium, sometimes the politician investigates, and sometimes the information is false. The lobbyists and the electorate benefit from the possibility of lobbying when the politician would otherwise vote in ignorance, but not when he would otherwise acquire his own information. The politician benefits in either case. Lobbying is most socially useful when the politician's investigation costs are high, when he is more certain of the electorate's views, and when the issue is less important.