In comments, Sam King-Walters asks about “counterfactual Mexicos.” Short version: I think it’s a fun essay, and John Coatsworth is a brilliant economic historian, but I don’t think the conclusions are quite right.
The essay, which I first read back in 2006, postulates three counterfactual scenarios for Mexico. In the first, Mexico declares independence in 1776 instead of 1821. In the second, Mexico declares independence between 1796 and 1808. In the third, independence happens on schedule, but the United States wins the War of 1812 and as a result does not invade Mexico in 1846.
In the first scenario, the U.S. loses the war of independence. (That is almost certainly true, although as Coatsworth concedes, the possibility of a Mexican independence revolt in 1776 is zero. But let’s run with it.) The assumption is that Mexico remains chaotic for the same period as it did in reality, but since the chaos starts in 1776 instead of 1821 economic growth begin commensurately early. He allows economic growth to start in 1800 and doubles population growth. He also halves the growth of thirteen colonies laboring under British rule.
The problems? Well, first, I have no idea why continued British rule would halve the growth of the thirteen colonies. No, seriously, I have no idea. British taxes were not onerous and foreign trade did not drive American growth during the period. Nor is it likely that London would have prevented western settlement from occuring for very long, the Proclamation of 1763 notwithstanding. The slowdown in American growth just does not make sense; I need to hear a better justification to believe that a hypothetical British North America would have grown much slower than the actual United States.
As for the acceleration in Mexican growth, well, it ignores the contributions of one John Coatsworth. Political instability wasn’t the only reason for slow growth; the country inherited some pretty lousy institutions from Spain. In addition, it had a terrible geography, which required railroads. It is plausible that a more stable Mexico might have started to build railroads around the same time as Spain did (1848), but that advances the onset of economic growth by only 25 years. And even that is not clear: the demand for industrial metals drove Mexico’s economic growth in the late 19th-century. The demand for those metals would not change because Mexico became independent earlier. There is no reason why the country could not have had 100 years of independent chaos instead of 55. (And let’s remember that Mexico actually had 65 years of chaos; the last ten years of Spanish rule were a mess.)
The above objections also apply to the scenario in which Mexico declares independence between 1796 and 1808. That said, Mexican independence during this period could well have led to Louisiana becoming part of Canada, and that would have greatly changed later history! Unless, of course, Britain transferred all or part of Louisiana to the United States, which is a not-improbable outcome.
It is true that Mexico would have benefitted from holding on to the territories lost to United States. But it is not true that Mexico would have held them with a British buffer or that Mexico would be much richer today. Would Mexico have held California? Maybe ... but with no American threat, London might have seen a very nice chance to take the territory for itself. Or, even more likely, the Californios would have declared independence. And even had Mexico held on to the territory, it is completely unclear to me why it would be any richer than the similar territories that Mexico retained after 1848. Sure, a Mexico with more area and population like Nuevo León and less like Chiapas is a richer Mexico, but that is not the scenario that the essay implies.
The final scenario (where the U.S. wins the War of 1812) fails for all of the above reasons plus a few more. First, it would have implied a declaration of independence by the Mexican elite in the middle of the Hidalgo Revolt, and that was not going to happen. Second, an American victory in the war of 1812 would have made American expansion into Mexico even more likely, as the country tried to preserve sectional balance between the free North and the slave South. Finally, even had the U.S. won the War and 1812, and even had said victory short-circuited an American invasion, and even had Mexico declared independence early, there is no reason to think that independent Mexico would have exhibited any less instability or started to grow any earlier.
Mexico has missed many opportunities (and grabbed others; things could have easily been worse!) but these three are not, I think, among them.