S. Giovanni, Parties and Party Systems, p.350, 1976.

, Central and eastern europe

M. Hinich and M. Munger, Analytical Politics, p.113, 1997.

I. Budge, D. Robertson, and D. Hearl, Ideology, Strategy and Party Change, 1987.

M. Laver and B. Hunt, Party Policy in Modern Democracies, 1992.

M. Hinich, Analytical Politics, 103; and Laver and Hunt, Party Policy in Modern Democracies, p.12

M. Gabel and J. D. Huber, Putting Parties in Their Place, American Journal of Political Science, vol.44, p.96, 2000.

, The structure of this political space is based on three assumptions for effective comparability: 1. Dimensions are general-they are broadly formulated, and their content theoretically applies in all of the systems compared

, Dimensions are fixed-they do not change over time (although their salience and party positioning on them does change)

, Dimensions are conceptually orthogonal-although often empirically related, political space is conceived as euclidian space where dimensions are uncorrelated. This allows for seeing different correlations through the actual positioning of parties on the dimensions

M. Hinich, Analytical Politics, p.21

W. Riker, The Art of Political Manipulation, 1986.

R. Budge, . Hearl, . Ideology, P. Strategy, . Change;-ian et al., Mapping Policy Preferences: Estimates for Parties, Electors, and Governments, 1945.

J. A. Carmines, N. Stimson-;-gary-miller, and . Schofield, United We Stand? Intra-party Dissent in the eU on Issues of european Integration" (Presented at the biannual meeting of the european Union Studies association, Issue Evolution: Race and the Transformation of American Politics, vol.97, 1989.

M. Hinich, Analytical Politics, pp.57-59

W. Henry, W. R. Chappell, and . Keetch, Policy Motivation and Party Difference in a Dynamic Spatial Model of Party Competition, Policy and Party Competition, 22, 96. 13. Budge, Robertson, and Hearl, Ideology, Strategy and Party Change, vol.80, pp.884-86, 1986.

M. Seymore, S. Lipset, and . Rokkan, They include extreme left-and right-wing parties, green parties, Party Systems and Voter Alignments, 1967.

K. Strom, Behavioral Theory of Competitive Political Parties, vol.34, p.585, 1990.

L. Ezrow, On the Inverse Relationship between Votes and Proximity for Niche Parties, European Journal of Political Research, vol.47, issue.2, pp.206-226, 2008.

H. Daalder, Competition between Unequals: The Role of Mainstream Party Strategy in Niche Party Success, Search of the Center in european Party Systems, vol.78, p.3, 1984.

J. A. Stimson, The Tides of Consent, 2004.

J. Sundquist, Dynamics of the Party System: Alignment and Dealignment of Political Parties in the United States, 1983.

S. Carmines, Issue Evolution

. Miller and . Schofield, activists and Partisan Realignment in the United States, World Politics, vol.40, pp.194-234, 1988.

H. Kitschelt, Formation of Party Systems in east Central europe, Politics and Society, vol.20, 1992.

H. Kitschelt, Diversification and Reconfiguration of Party Systems in Postindustrial Democracies, Policy and Party Competition

R. Inglehart, Cultural Shift in Advanced Industrial Society, 1990.

M. Franklin, 383-405; and Liesbet Hooghe, gary Marks, and Carol Wilson, Electoral Change: Responses to Evolving Social and Attitudinal Structures in Western Countries, vol.35, pp.965-89, 1992.

, Left-Libertarian Parties"). We follow Hooghe et al. and use the terminology tan/gal (traditional, authoritarian, national/green, alternative, libertarian), east european Politics and Societies 23. This dimension takes on many guises in the literature: postmaterialist/materialist (Inglehart, Cultural Shift in Advanced Industrial Society); new politics/old politics, vol.39, pp.179-212, 2006.

L. Hooghe, R. Bakker, A. Brigevich, C. De-vries, E. Edwards et al., Reliability and Validity of Measuring Party Positions: The Chapel Hill expert Surveys of, European Journal of Political Research, vol.49, p.5, 2002.

L. Ray, ;. Gary-marks, M. Steenbergen, ;. , and H. , 27. To ensure the robustness of these results, we ran the analysis using various rotation and retention mechanisms. Our substantive findings remained unchanged. 28. Unfortunately we do not have corresponding data for previous time points, Measuring Party Orientations towards european Integration: Results from and expert Survey, vol.36, p.8, 1999.

. Marks, 30. In austria |b| = 1.226; Spain |b| = 1.395; Poland |b| = 1.044; Slovenia |b| = 1.491. 31. Lipset and Rokkan, Party Systems and Voter Alignments. 32. Our findings are robust across various factor analysis techniques. The results are substantively unchanged under different factor retention and rotation mechanisms. For both the social and economic factors, the correlation coefficients between the varimax and oblique rotated factors is r = .999. 33. James adams, Michael Clark, Lawrence ezrow, and garrett glasgow, "are Niche Parties Fundamentally Different from Mainstream Parties? The Causes and electoral Consequences of Western european Parties' Policy Shifts, American Journal of Political Science, vol.50, issue.3, pp.513-542, 1976.

;. Meguid, Competition between Unequals" include regional/ethnic parties in their analyses. See note 15. 35. It results in a 1.003 point shift on factor scale with a range of 5.45 points. 36. a 10 percent vote increase shifts the importance of economic issues, Competition between Unequals" and Party Competition between Unequals. 34. Note that neither adams

, Rovny was a PhD candidate at the Department of Political Science at the University of North Carolina at Chapel Hill at the time this article was written. He is currently a Post-Doctoral Researcher in the Center for european Research at the University of gothenburg, He has published articles in the European Journal of Political Research, as well as in political science journals in Belgium and the Czech Republic. His research interests include party politics

E. E. , Edwards is the executive director of the Center for european Studies at the University of North Carolina at Chapel Hill. Her articles have appeared in Comparative Political Studies, European Union Politics, and Party Politics (forthcoming)