These will stump you!
Population management is unethical. And it's also infeasible given that most of the growth of global pop will occur in Africa and the Middle East.
What's the catch with -> instead of growing our population to keep the economy in fruitful expansion ad infinitum (contributing more climate damage, resource depletion, eventually moving to Mars, etc) why not actively downsize consumption and productivity? In other words, in the same way we manage the economy to improve productivity and growth, why not manage a soft-landing to a sustainable population target?