 Various authors theorize that the reason for these inconsistencies may lie in the Mestizo identity promoted by the Mexican government, which reportedly led to people who are not biologically Mestizos to identify themselves as such.The following table is a compilation of (when possible) official nationwide surveys conducted by the Mexican government who have attempted to quantify different Mexican ethnic groups.Given that for the most part each ethnic group was estimated by different surveys, with different methodologies and years apart rather than on a single comprehensive racial census, some groups could overlap with others and be overestimated or underestimated.