Crop yield is one of the most common proxies for agricultural
productivity, with yield generally estimated as the harvested
weight divided by harvested area. New estimates using data
from the 2008 Tanzania National Panel Survey Living
Standards Measurement Study – Integrated Surveys on
Agriculture (LSMS-ISA) reveal that on almost a quarter of rice
plots surveyed, farmers harvested less area than they
planted. We find that common measures of yield that omit
this “null production area” may significantly overestimate
land productivity, particularly for poorer farmers and those
with smaller plots.