W. Szczesny, A. Ciok, T. Kowalczyk, E. Pleszczynska, W. Wysocki

A statistical comparative study of 1993 and 1997 Elections to the polish Parliament

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Abstract

Results of the elections to the Polish Parliament in 1993 and 1997 are taken into consideration. The authors are using their own statistical tools, in particular the grade correspondence analysis, to the tables with votes numbers gained by particular political parties in any election region. Rows and columns of each table were permuted until a maximal value of the grade correlation coefficient was found. The trend in any optimally permuted table forms a non-decreasing relation between parties and regions such that the cells on and near this relation tend to be overrepresented (i.e. tend to be larger than would result from strict proportionality to the total number of votes gained by the party in all regions and to the total number of voters in the region). The analysis relies on seeking and comparing the main trends concerning parties-regions relations in 1993 and 1997.

The optimal trends and the optimal orders of parties and regions turned to be very similar for both elections; rather small changes concerned the total votes numbers gained in both occasions by particular parties. Leaving a thorough interpretation of the trends to politicians, sociologists and economists, the authors limit themselves to suggest that the orders of regions are bound with their actual economical situation and orders of parties - with their declarations on required economical reforms.

Technical details have been omitted but they could be found in cited sources. However, we hope that the reader would understand the graphically presented results without a deeper insight into the statistical background. A tentative example with fictitious data (4 parties, 5 regions) is introduced to illustrate the calculations.

Key words: data analysis, grade correspondence analysis, overrepresentation index, grade correlation coefficient (Spearman's rho), monotone dependence, party (region) profile, visualization.