Study of spatial models of political party competition with starting point the Downs model. therefor political experts were asked to scale several political parties on a socio-economic left-right scale with 100 points. ideological left-right optimum of political parties / margins of the optimum / influence of 2 political objectives for each party: 1. the votes of an as large as possible proportion of the electorate 2. the actualization of ideological preferences / actual position on left-right scale of parties / deviation of ideological optimum / experts voting behaviour at national elections 1989 / occupational group expert belongs to: parliamentary journalists, ex-politicians, social scientists / constructed variables. Background variables: politics