J.R. Ireland describes what happened to Puerto Rico’s economy when the minimum wage was raised to the mainland level by congress in 1974:
Prior to 1974, Puerto Rico had its own minimum wage and was not tethered to the general American wage. Then, in their infinite wisdom, the US Congress decided to normalize the minimum wage across all US territories and passed legislation making Puerto Rico’s minimum wage the same as the American wage had always been.
Well what happened next, you might ask? The economy imploded. Puerto Rico had an unemployment rate around 12% and an employment to population ratio of approximately 78% pretty much continuously between 1960 and 1974. The numbers had gone up a bit — they had come down a bit — but overall, year in and year out, you could look at Puerto Rico and be sure that the unemployment rate would be between 10 and 14 percent and the employment to population ration would be between 75 and 80 percent. You could set your watch by this kind of consistency.
Then Puerto Rico’s minimum wage was raised substantially beginning in 1974. The Puerto Rican unemployment rate then proceeded to increase for four consecutive years until it peaked at 20%. It roughly plateaued for half a decade or so, and then it went up again until Puerto Rico had an unemployment rate of 25% by 1984. Meanwhile, the employment to population ratio fell from 78% to 60% and has never recovered.
It is not just me pointing out the absolutely catastrophic consequences of the minimum wage increase in Puerto Rico — the National Bureau on Economic Research agrees. According to them:
Imposing the U.S.-level minimum reduced total island employment by 8-10 percent compared to the level that would have prevailed had the minimum been the same proportion of average wages as in the United States. In addition, it reallocated labor across industries, greatly reducing jobs in low-wage sectors that had to raise minima substantially to reach federal levels. (3) Migrants from Puerto Rico to the United States are drawn largely from persons jobless on the island, with characteristics that make them liable to have been disemployed by the minimum wage. As the Puerto Rican minimum rose toward U.S. levels, the education of migrants fell below that of nonmigrants. (4) Migration was critical in allowing Puerto Rico to institute U.S.-level minimum wages and played a major role in the long term growth of real earnings in Puerto Rico by reducing the labor supply and raising the average qualifications of workers on the island.
In other words, the minimum wage increase caused massive unemployment, forced hundreds of thousands of unemployed Puerto Ricans to flee the island because there were no jobs, and the only reason the entire territory wasn’t rendered destitute is because the poorest Puerto Ricans all moved to Chicago or New York rather than choosing to remain unemployed on the island itself.