Motivating poorly paid enumerators to do their job properly is another problem.

ECONOMIST: China's ten-yearly census: The world's biggest headcount | The

Still, state media reports that many are evading the enumerators.

ECONOMIST: China's ten-yearly census: The world's biggest headcount | The

Ironically, in light of its troubles with the law, Acorn was selected in March to assist the U.S. Census in reaching out to minority communities and recruiting census enumerators for the count next year.

WSJ: More Acorn Voter Fraud Comes to Light

And always the enumerators face practical difficulties.

ECONOMIST: Migration statistics