The Indirect Sampling as a General Approach for Defining Unbiased Sampling Strategies for integrated Agricultural Surveys

The Global Strategy to Improve Agricultural and Rural Statistics, endorsed at the United Nations Statistical Commission in February 2010, underlines the need to ensure the consistency and the integration of agricultural statistics into national statistical systems, allowing building agricultural statistics in which the information on land parcels, households and farms are interlinked. The sample strategy, presented in this paper, achieves this strategic objective and simultaneously provides consistent statistics on the environmental, social and economic dimensions of agriculture. The methodological approach extends the use of indirect sampling to the case of producing integrated estimates on three target populations. The proposed techniques are quite flexible and may be tailored to the different informative contexts which characterize the production of agricultural statistics in developing countries. Furthermore, under quite general conditions, they allow to produce unbiased statistics, overcoming the majority of the problems caused by imperfect sampling frames