In the global population and workforce exchange system Ukraine acts primarily as a donor country. According to the estimates of the M.V. Ptukha Institute for Demography and Social Studies, Ukrainian National Academy of Sciences (hereafter IDSS), in 2008 the total number of Ukrainian labor migrants were 2,120,000 people (IOM, 2011). This estimate of the number of labor migrants relies on the Modular Population Survey of Labour Migration Issues from 20081 (hereafter the 2008 survey), carried out by the State Statistics Service of Ukraine (Ukrainian Center of Social Reform and Ukrainian State Statistics Committee, 2009). However, it also takes into account the stocks of labor migrants not covered by this survey, namely: persons who started to work abroad more than 3.5 years before the survey and who have not returned to Ukraine since then; migrants older than employable age (men 60 years old and senior, women 55 years old and senior); and border commuters (Pozniak, 2012). The main destination countries for labor emigrants from Ukraine are Russia (around 40%), Italy (almost a quarter), Poland, the Czech Republic, Portugal, Spain and Hungary. In total over half of all Ukrainian labor migrants work in the European Union. In this explanatory note circular migrants are understood as those who made one or more labor trips abroad and returns. There are two types of circular migrants. Migrants who made only one roundtrip between the places of origin and destination are described as ?return migrants? (Newland, 2009) and migrants who made more than one trip are defined as ?pure circular migrants?