ACTA SCIENTIARUM POLONORUM - SGGW

70 A. Ptak-Chmielewskastatistics, while others omit such data. In some states reports concern enterprises, inothers local units. In some countries foreign companies are included, in others not.A definition of enterprise birth was established at the EU level [European Commission,Regulation no. 2700/98]. According to this definition, a birth does not refer to a newenterprise that came to life due to a split-up of previously existing unit or a change inthe character of activity. As in the case of deaths, takeovers and mergers are not takeninto account.Birth rates and death rates are calculated as a proportion of entries and exits of enterprisesduring the reference year to the mean number of active enterprises in the referenceyear (in percent). The difference between these two ratios gives the real dynamicsin enterprises population in a given year [Business demography in Europe, Enterprisepublications, EC 2002, p. 14].Birth rates and death rates are calculated according to the following formulae:Number of birthstBirth Ratet= 100%(1)Mean number of active enterprisestNumber of deathstDeath Ratet= 100%(2)Mean number of active enterprisestRecently the interest in business demography in Poland has increased significantly.First works strictly dedicated to the analysis of the enterprise population dynamics developmenthave appeared. Dominiak and Markowicz’s papers [Dominiak 2005, Markowicz2008] present definitions of business demography as a research discipline as wellas detailed definitions of demographic ratios. These works refer to SME sector to a greatdegree. Studies on bigger companies and corporations were published by Rogowski andSocha [Rogowski, Socha 2005].Business demography analyses in Poland are not systemized. Markowicz attempts toenumerate some basic measures connected with the description of enterprise population.Author [Markowicz 2008] lists numerous distinct measures, which makes the analysisslightly unclear for the readers. Her understanding of the rate of enterprises emerging andexiting in comparison with the ratio of births and deaths is quite fuzzy.Some basic measures and definitions coherent with Eurostat publications were introducedby Ptak-Chmielewska in papers published in 2009 and 2010 [Ptak-Chmielewska2009, 2010].However, one needs to account for some weaknesses of REGON register measuresas they do not clearly specify the real activity moment. A record in a business registerdoes not always mean the actual start of activity. In this paper the analyses are based onmeasures and definitions presented and published by Eurostat, which allows to makeActa Sci. Pol.