This article analyses population changes in North-West regions of Russia (the former North-Western economic zone and the Kaliningrad region) and the Baltics at the level of urban districts and municipalities. The cohort component method is used to analyze the youth population dynamics in the administrative territorial units of this level, which makes it possible to estimate the international (intraregional) migration of this population group. This method is used quite rarely, yet it is more accurate in studying the shifts in distribution of this group of population than current statistics. The article uses the data of the last two censuses (2000 and 2010), namely, the population size and the age and gender composition. In order to demonstrate the core-periphery relationship, the authors identified the core ATUs (national and regional capitals and capital areas), whereas the other units were grouped by their remoteness from the center. The analysis shows that in the countries and regions studied, population concentrates in the capitals and capital areas, whereas the periphery loses population at a fast rate. The centripetal movement is especially pronounced with the youth; moreover, it affects not only the size but also its structure of population in the core and periphery areas, which aggravates the processes of depopulation and ageing.