Belgium belongs to the group of countries whose economic structure in terms of ﬁ rm size is close to the European average (Table 2.1). There are only a few minor differences from the European mainstream. The employment share of the Belgian companies belonging to Europe’s 500 largest businesses is slightly below the average, whereas their number is above. Furthermore, the proportion of the micro ﬁ rms and their employment share is somewhat higher, whereas the corresponding percentages of small companies are lower. In contrast to the structure of ﬁ rms, the Belgian economy strongly deviates from the European average with regard to foreign trade penetration. With the sum of exports and imports (i.e. goods and services) representing 172.7 per cent of GDP in 2003, the Belgian economy surpasses almost all other countries in openness.1 This has directed special attention to the issue of comparative labour costs, as we will see below.