But that estimate was based almost entirely on expert input instead of nationally representative random sample surveys – the gold standard of research design.

For its 2016 Global Slavery Index, Walk Free partnered with Gallup and commissioned random sample surveys for 25 countries.

By partnering with the world’s premier polling organization and using advanced survey techniques, Walk Free was able to embark on groundbreaking work.

However, Walk Free ended up generating a global estimate for 168 nations, not just the 25 nations it had surveyed. That meant for the other countries in its 2016 estimate, Walk Free relied on both expert input and statistical techniques – and didn’t solely use nationally representative survey data.

That same technique of mixing survey data with statistical techniques applies to the U.N.’s 2017 and 2022 global estimates.

For its 2017 estimate, the U.N., working with Walk Free and other organizations, commissioned surveys in 48 countries from 2014 to 2016. And for its 2022 report, the U.N. gathered data from 68 countries to estimate forced marriage and from 75 countries to estimate forced labor.

Though the report revealed a clear increase in the number of nationally representative surveys to generate these global estimates, it still fell short in measuring a majority of the countries in the world.

There are currently 193 member states in the United Nations. The U.N.’s 2022 global estimate that surveyed 75 countries to estimate forced labor did not survey the remaining 118 countries, instead basing its numbers on expert input and statistical techniques.

Nor did the U.N. publish a full list of the countries for which it conducted nationally representative surveys in 2017. It’s difficult, then, to know how many of those 48 countries sampled for the 2017 report were repeated for the 2022 report.

We also don’t have publicly available data for those 48 countries, let alone the countries surveyed for the 2022 global estimate.

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