This paper assesses the impact of three methodologies
of food data collection on the welfare distribution, and
poverty and inequality measures in Niger. The first methodology
is a 7-day recall period, the second one is a usual
month, and the third one is a 7-day diary. The paper finds
that there is a difference in the distribution of welfare
between, on the one hand, the two first methodologies
(7-day recall and a usual month, which give results close
to each other) and, on the other hand, the 7-day diary
method. When considering annual per capita consumption,
the 7-day diary lags the 7-day recall by 28 percent.
This gap is not only at the mean of the distribution, it
has been found at any level. These differences lead to differences
in poverty and inequality measures even when
alternate poverty lines are used. This study underscores
the problem that many developing countries face when it
comes to monitoring poverty indicators over time where
different methodologies have been used over the years.