At Economic Logic they continue
Matthias Doepke and Fabrizio Zilibotti add further arguments against bans and boycotts by considering their political economy aspect. A boycott or a ban from outside directly impacts only the export sector. Children are thus pushed to the non-traded sector, typically local agriculture where children engage in physically less demanding work than adults. Thus specialization occurs and children do not compete with adults. There is no local support for a child labor ban.
If there is no outside intervention, then children stay in the export sector and are in competition with the local unskilled adults. Those will now want to support a local ban of child labor so as to get rid of this competition for jobs. Thus, paradoxically, an attitude of laissez-faire in the rest of the world would lead to a child labor ban. Intervening would prevent the ban from happening.