APPLICATION OF CLASSIFICATION TREES TO ANALYZE INCOME DISTRIBUTION IN POLAND

The aim of presented research is to identify factors that determine wages in Poland and to find out if gender pay gap exists, applying classification trees. For the grouping variable i.e. net income from the main place of employment we construct clusters of respondents that are created due to such features as: gender, education, employment contract, economic, occupation, additional job, size of enterprise, measured by the number of employees, age and job seniority in years. Investigation is provided applying data from the Polish Labor Force Survey in the years 2003, 2006 and 2009.