Is there a county border effect in spatial income differences in Hungary?

The economic and social importance of administrative borders can be examined from the point of view of internal homogeneity and external heterogeneity of the delimited spatial units and from the point of view of the effect on the intensity of spatial interactions. This paper deals with the first question. Hungarian county borders can be treated as sharp limits from the administrative point of view. However, choropleth maps with county borders can suggest that county borders are sharp limits for the social and economic indicators also. It is a conceptually interesting question whether presenting data at county level is justified by the sharp differences of various indicators along the county borders or it is determined only by the availability of data. The aim of this study is to examine empirically the existence or non-existence of the county border effect by the example of spatial distribution of personal incomes in Hungary. The analysis is possible due to the availability of personal income data at the level of more than 3000 Hungarian settlements. The analysis is conducted by the comparison of average personal incomes of settlements of following areas: average of own county, average of neighbouring county, average of neighbouring settlements, average of neighbouring settlements in own county, average of neighbouring settlements in neighbouring county. The results show that county borders have effect only in those cases, where the border is determined by a sharp geographical barrier, namely Danube River and Lake Balaton. The settlements are more similar to the close settlements of a neighbouring county than to the average of own county.