This study published in Nature [0] says that rural populations in particular are typically UNDERCOUNTED (exactly like the Papa New Guinea in the OP's article), and that this happens at similar rates across poorer and wealthier countries: "no clear effect of country income on the accuracies of the five datasets can be observed."
alt Hacker News
Do you have specific examples?
This study published in Nature [0] says that rural populations in particular are typically UNDERCOUNTED (exactly like the Papa New Guinea in the OP's article), and that this happens at similar rates across poorer and wealthier countries: "no clear effect of country income on the accuracies of the five datasets can be observed."
[0]: https://www.nature.com/articles/s41467-025-56906-7