Multiple Frames Surveys: a promising tool for agricultural statistics

For agricultural surveys, a Dual Frame design combining the customary area frame with an additional list frame has been suggested in the 70s (Hartley, Sankhya 1974) for reducing costs and improving estimate accuracy. The availability of 2 or more partial list frames supporting the area frame is often the case in modern applications so that a more general Multiple Frame design appears as a promising tool for agricul- tural surveys. Some major issues will be discussed such as: i) the selection from overlapping frames under a sampling design able to exploit all the available auxiliary information including sub-area sizes; and ii) a weighting system at the estimation stage, feasible for dealing with the increased probability to be selected in the final sample for farms also included in one or more lists and, at the same time, to be selected more than once, from different lists, even if this have not occurred in practice.