For each OECD country, data are collected at two sub-national levels: Territorial level 2 (TL2), which refers to the 337 large regions of the OECD area. Territorial Level 3 (TL3), which refers to the 1709 small regions of the OECD area. In any analytical study conducted at sub-national levels, the choice of the territorial unit is of prime importance. The territorial grids used in this database are officially established and relatively stable in all member countries, and are used by many as a framework for implementing regional policies. Regions in OECD Member Countries have been classified according to two territorial levels (TL). The higher level (Territorial Level 2) consists of about 362 macro-regions while the lower level (Territorial Level 3) is composed of 1794 micro-regions. This classification - which, for European countries, is largely consistent with the Eurostat classification - facilitates greater comparability of regions at the same territorial level. The differences with the Eurostat NUTS classification concern Belgium, Greece and the Netherlands where the NUTS 2 level correspond to the OECD TL3 and Germany where the NUTS1 corresponds to the OECD TL2 and the OECD TL3 corresponds to 97 spatial planning regions (Groups of Kreise). For the United Kingdom the Eurostat NUTS1 corresponds to the OECD TL2. Due to limited data availability, labour market indicators in Canada and Australia are presented for a different grid (groups of TL3 regions in the case of Canada). Since these breakdowns are not part of the OECD official territorial grids, for the sake of simplicity they are labelled as Non Official Grids (NOG). National values have been computed based on regional estimates. For this reason, it is possible that in some cases these values differ from national statistics.