Answer:
The costs of passing a bill that prohibits child labor is precisely that all the labor that children could have provided for the economy is forgone. So in pure economic terms, there is a loss of value, a sunk cost.
However, the benefit is both economic, and social. The economic benefit is that children will instead go to school, and educate themselves to become more productive workers in the future. And the social benefit is a fairer society, and wealthier too.
It allowed women to vote and anyone older than 18 years
