Sampling system for LUCAS 2015

The sampling design of LUCAS 2015 took into account experience from previous campaigns. While remaining a Two-phase sampling scheme, efforts were focused in reducing the set of excluded points from the second phase sample, which are placed in difficult and inaccessible areas. This action was implemented both through: 1. the improvement of the first phase sample (LUCAS master sample) by updating each point of the grid with the most recent available information (NUTS borders, road network, elevation, Corine Land Cover results (CLC2006)) 2. the fine-tuning of the past rule for eligibility of the point introducing an additional new indicator of accessibility based on CLC; the final criteria combine all the auxiliary information [Elevation, Road distance, Slope, CLC indicator]. However excluded points will remain a likely source of bias which has to be treated separately from the field survey. The corresponding excluded area needs to be covered with a complementary photo-interpretation operation, including an ex-post photo-interpretation also for 2012 and 2009 surveys. Such a photo-interpretation task, although important and linked to the sampling exercise, is not addressed in this document but represents next priority for the future work.