The National Agricultural Statistics Service (NASS) conducts the census of agriculture (a
complete count of US farms and ranches) every five years. Sample surveys, including the
June area survey (JAS), are carried out annually to obtain estimates of many of the same
agricultural quantities as the census. Due to the large number of operators surveyed and the
complete coverage provided by the census, its numbers are considered more accurate than
those derived from the much smaller scale sample surveys. An interesting question is
whether census figures for specific survey items can be used in conjunction with survey
data to improve estimation accuracy for non-census years. Because of its relative stability
over time, the survey item considered most likely to benefit from such an approach is
number of farms in a state.
Two proposed methods for projecting census counts of number of farms to subsequent
non-census years are evaluated. The first method updates the census figure to the current
year using JAS data only, while the second makes additional use of official NASS state
level estimates of number of farms for the previous year (if it wasn’t a census year). The
two methods are identical for the first post-census year. The proposed estimators are
compared with area frame based and hybrid operational estimators for the years 2003-06 in
a study covering most of the lower 48 states, both at the state level and within categories
defined by farm value of sales. Variances are estimated using an extended delete-a-group
jackknife method