Slavery in Nepal was abolished only in 1921. Corvée, forced labor, was made illegal in 1952, but survived. It was only in 2000 that various sorts of coerced and bonded labor finally disappeared.
Why Nations Fail
Surely even the most kleptocratic dictator would be in favor of economic development. Economic development means greater income, greater taxes and more stuff to grab, so what’s not to like about it? But actually, it often doesn’t work that way.