It seems fairly evident that human trafficking has had an economical positive effect on countries who practiced it. It is an common observed fact that the current construction sector is dependent on human trafficking and most current construction projects would fail to meet their goals without a steady stream of cheap, untaxed illegal labor that do not need to follow safety regulations.

However for people who work in those sectors the picture tend to look differently with wages and good safety practices being suppressed. Construction companies that follow regulations and pay taxes for all their employees will loose in the competitive market. The effect on the economy may be a net-positive, and it may also be true that most countries could not contain growth if construction actually cost as much as it had to without the illegal practices, but that is all multiple aspects of the same issue.