This article proposes a model of endogenous protection by integrating
informed and non-informed voters in the population. The model also
distinguishes between interest groups and pressure groups, by considering that
the members of one interest group do not necessarily organize as a pressure
group (lobby). The endogenous tariff stemming from the model is an increasing
function of the relative influence of the lobby, and the aforementioned
function itself increases in accordance with the part of non-informed voters.
This framework avoids formalizing contributions. It also permits to show that
the conditions of the lobbying’s efficiency depend on the nature of the free
rider comportment of the interest group members.
 Buchanan, J.M. and Tullock, G. (1962) The Calculus of Consent: Logical Foundations for Constitutional Democracy. The University of Michigan Press, Michigan.
 Horgos, D. and Zimmermann, K.W. (2009) Interest Groups and Economic Performance: Some New Evidence. Public Choice, 138, 301-315. http://dx.doi.org/10.1007/s11127-008-9360-4
 Laband, D.N. and Sophocleus, J.P. (1988) The Social Cost of Rent-Seeking: First Estimates. Public Choice, 58, 269-275. http://dx.doi.org/10.1007/BF00155672
 Baldwin, R.E. (1982) The Political Economy of Protectionism. In: Bhagwati, J.N., Ed., Import Competition and Response, University of Chicago Press, Chicago, 263-292.
 Peltzman, S. (1976) Toward a More General Theory of Regulation. The Journal of Law and Economics, 19, 211-248.http://dx.doi.org/10.1086/466865
 Hillman, A.L. (1982) Declining Industries and Political-Support Protectionist Motives. American Economic Review, 72, 1180-1187.
 Grossman, G. and Helpman, E. (1994) Protection for Sale. American Economic Review, 84, 833-850.
 Grossman, G. and Helpman E. (1995a) The Politics of Free-Trade Agreements. American Economic Review, 85, 667-690.
 McCalman, P. (2004) Protection for Sale and Trade Liberalization: An Empirical Investigation. Review of International Economics, 12, 81-94. http://dx.doi.org/10.1111/j.1467-9396.2004.00432.x
 Baron, D.P. (1994) Electoral Competition with Informed and Uninformed Voters. American Political Science Review, 88, 33-47. http://dx.doi.org/10.2307/2944880
 Ansolabehere, S., de Figueiredo, J.M. and Snyder Jr, J.M. (2003) Why Is There So Little Money in US Politics. Journal of Economic Perspectives, 17, 105-130.http://dx.doi.org/10.1257/089533003321164976
 Desai, R.M. and Olofsgard, A. (2011) The Costs of Political Influence: Firm-Level Evidence From Developing Countries. Quarterly Journal of Political Science, 6, 137-178.http://dx.doi.org/10.1561/100.00010094
 Wenegast, T. (2010) Uninformed Voters for Sale: Electoral Competition, Information and Interest Groups in the US. Kyklos, 63, 271-300. http://dx.doi.org/10.1111/j.1467-6435.2010.00473.x
 Olson, M. (1966) The Logic of Collective Action. Harvard University Press, Cambridge.
 Helpman, E. (1995) Politics and Trade Policy. NBER Working Papers Series, 5309, 36.
 Grossman, G. and Helpman, E. (1995-b) Trade Wars and Trade Talks. Journal of Political Economy, 103, 675-708.http://dx.doi.org/10.1086/261999
 Pincus, J.J. (1975) Pressure Groups and the Pattern of Tariffs. Journal of Political Economy, 83, 757-778.http://dx.doi.org/10.1086/260354
 Yasar, M., Rejesus, R.M., Chen, Y. and Chakravorty, U. (2011) Political Influence of Firms in the Tradables and Non-Tradables Sectors: A Cross-Country Analysis. Economics & Politics, 23, 297-312. http://dx.doi.org/10.1111/j.1468-0343.2011.00386.x
 Brock, W.A. and Magee, S.P. (1978) The Economics of Special Interest Politics: The Case of the Tariff. American Economic Association Papers and Proceedings, 68, 246-250.
 Richter, B.K., Samphantharak, K. and Timmons, J.F. (2009) Lobbying and Taxes. American Journal of Political Science, 53, 893-909. http://dx.doi.org/10.1111/j.1540-5907.2009.00407.x
 Arceneaux, K. and Huber, G.H. (2007) Identifying the Persuasive Effects of Presidential Advertising. American Journal of Political Science, 51, 957-977.http://dx.doi.org/10.1111/j.1540-5907.2007.00291.x
 Black, D. (1958) The Theory of Committees and Elections. Cambridge University Press, Cambridge.
 Becker, G.S. (1983) A Theory of Competition among Pressure Groups for Political Influence. Quarterly Journal of Economics, 98, 371-400. http://dx.doi.org/10.2307/1886017
 Wellisz, S. and Wilson, J.D. (1986) Lobbying and Tariff Formation: A Deadweight Loss Consideration. Journal of International Economics, 20, 367-375. http://dx.doi.org/10.1016/0022-1996(86)90028-0
 The Economist (2008) The Battle of Smoot-Hawley. Finance & Economics, 4.
 Bloningen, B. (2008) New Evidence on the Formation of Trade Policy Preferences. NBER Working Papers No. 14627.