Comparative analysis of alternative sampling plans to create a farm accountancy data network for the agricultural sector of Navarra

This study presents the method that was followed and the results of the analysis for establishing a sampling plan for the Farm Accountancy Data Network (FADN) of the commercial agricultural sector of the Spanish Autonomous Community of Navarra. The first part of the study presents the categories considered of the different stratification criteria for the commercial farms of Navarra: geographical units (subregions), types of farming (TF) and economic size in ESU (European Size Unit). Then the authors define sampling plans with different objectives to be compared. These objectives are: i) maximum accuracy in the estimation of the Standard Gross Margin (SGM) for the whole of the commercial agricultural sector: ii) the same accuracy in the various types of farming (TF) and iii) the same accuracy in the individual strata. Special attention is given to the affects of introducing geographical units as a stratification criterion. Given the sample size and the characteristics of the population of commercial farms in Navarra the plan without geographical stratification that gives aproximately the same accuracy in each TF seems to be the most suitable sampling plan for the FADN of this region. Even though this study is limited to Navarra, it may be of help when considering sampling plans for FADN not only in other Autonomous Communities but also on a national sca