Using the european Union statistics on Income and living Conditions data for the year 2009, the authors evaluate how vertical and horizontal job segregation explains the differential between fulltime and part-time pay for prime-age women in four european countries: austria, Italy, Poland, and the United Kingdom. the selected countries are representative of different welfare state regimes, labor market regulations, and extents and forms of parttime employment. Full-time hourly wages exceed part-time hourly wages, especially in market-oriented economies, such as Poland and the United Kingdom. Results using the neuman-Oaxaca decomposition methods show that most of the full-time-part-time wage gap is driven by job segregation, especially its vertical dimension. vertical segregation explains an especially large part of the pay gap in Poland and the United Kingdom, where, more than elsewhere, part-timers are concentrated in low-skilled occupations and the wage disparities across occupations are quite large. P art-time (Pt) work is by far the most widespread form of nonstandard work in europe, and it is one of the most gendered-most part-timers are women. It is also a type of work with low wage prospects. several recent studies have shown that female part-timers have lower hourly earnings than female full-timers (mcginnity and mcmanus 2007; Bardasi and gornick 2009) and that a sizable part of this wage penalty is explained by worker characteristics such as low levels of education and more dependent children.In addition, horizontal segregation, that is, the concentration of part-timers in certain types of firms or economic sectors, is also a key factor in explaining the full-time (Ft)-Pt wage gap. the role of vertical segregation, that is