Introduction

Economic downturns, expansions of the European Union, demographic shifts and international wage gaps seem to push people to move in numbers, dynamics and ways not seen before (Santo Tomas, Summers & Clemens 2009). These dynamics create challenges for measuring and researching new phenomena that are emerging and shifting.

The lack of migration data creates a significant blind spot in the context of current economic and social realities. The migration flows following the 2004 and 2007 EU enlargements have shed additional light on manifest shortages of migration data. With current migration data we have difficulty answering crucial questions: how many migrants left, who left, how did migrants select their destinations, how did migrants fare at their destinations, why and when did they move, how many returned and to what extent does back-and-forth migration occur today, as well as whether and to what extent legal migration affects irregular migration (Santo Tomas, Summers & Clemens 2009).

The aim of this chapter is to describe, discuss and evaluate data sources and their ability to measure and analyse post-accession information, including migration flows and their patterns, categories of migrants and their statuses, and mechanisms, causes and implications of post-accession migration. The analysis presented here largely draws on research accumulated for the Polish case study. However, one must first consider the nature of post-accession migration in general.

Unique patterns of post-accession migration flows

A question that merits consideration is whether post-accession migration is any different than the waves of migration during pre-accession periods, which mostly cover the timeframe of the systemic transition in CEE. As argued by Engbersen and Snel in this volume, post-accession migration can be classified as ‘new migration’. This suggests the need for a new methodological approach that accounts for the novel and complex usage of established migration data sources, especially as regards the uniqueness or shared characteristics of pre- and post-accession migration waves.

Garapich (2008) argues that post-accession migration is a continuation of migration from a period of systemic transition; the upswing in mobility occurred long before 1 May 2004. Simultaneously, however, Garapich makes note of some unique characteristics in the post-accession wave, namely, that it is demand-driven, depending on the situation in the receiving labour markets, and that it involves migrants who are self-conscious about their labour market status, as reflected in the visible changes in their substitution of irregularity with regularity and the civic attitudes they exhibit.