Mexico's poverty agency on Friday criticized the national statistics institute for "irregular" changes in the methodology of measuring household income that showed the income of poor Mexicans had jumped by a third.
Earlier on Friday, the national statistics institute, INEGI, published its Module of Socioeconomic Conditions, saying that it had "improved the measurement of household income."
But the National Council for the Evaluation of Social Development Policy (CONEVAL), which measures poverty levels using INEGI's data, said the changes by the statistics institute were not credible.
INEGI did not immediately respond to a request for a comment.
CONEVAL is a decentralized government agency while INEGI is an autonomous public agency.
"A real increase of 33.6 percent of the income of the poorest households in the country in just one year is presented, which is not congruent with the trend that has been manifesting itself in other INEGI instruments and economic variables," CONEVAL said in a statement.
CONEVAL said that INEGI had changed its methodology without consulting CONEVAL and that it had not provided public documentation of the technical aspects behind the changes.