What I like to call the ascent of the Second World (that is, the second world of the 1950s) took place mostly between 1950 and 1980, though in some countries, the strongest phase of the ascent ended in the early 1970s.
Note that the ascent of the Second World was an era of the convergence of much of the Second World of the 1950s with Britain and the United States, not a narrowing of income gaps within that group of countries. In fact, the income gaps between the countries that were second-world in the 1950s had, on average, grown by 1973, only shrinking a little in the 1973-1980 period.
The countries, lands, and peoples I consider to have been a part of the Rise of the Second World include
1. Japan (but stronger than all those below, leading Japan to become the first of the East Asian Miracle countries).
2.1 Southern Italy (Hat Tip: pseudoerasmus)
3. Puerto Rico
4. Mexico and Brazil (but not the rest of LatAm).
5. Communist Eastern Europe (variable).
6. to a small extent, Canada, Denmark, and Finland (not shown).
7. Black America (a third-world people in a first-world country make a second-world society), especially 1959-1973. See Thomas Sowell on this. Note that this occurred during the Golden Age of American Black residential segregation.
8. Austria (though it was already close to the First World due to its unification with Germany in 1938-1945).
Turkey was an interesting outlier in all this, as while its electricity consumption per capita and economic complexity of goods exports (can’t find the link, but in 1960, virtually all of Turkey’s meager exports were pistachios -I think it was a PDF with export treemaps) grew at a reasonable pace since 1960, it didn’t experience the sort of economic miracle seen in the PIGS+Israel. Indeed, it only experienced any sign of convergence with the U.S. only after 2003. Its economic trajectory seems to be similar to that of Argentina, only less volatile. Turkiye delenda est.
Marked is the line between First and Second-World countries (around 44.2% of U.S. GDP/capita (PPP)), and the years 1973 (lots of things, but most importantly supply shocks and rough natural end of much convergence), 1982 (Latin American debt crisis), and 1991 (peak of the Axis Powers). I mentioned the Portugal-Mexico gap a couple days before.
Due to lack of data, much of Eastern Europe isn’t pictured. It is clear, however, that Romania suffered during the 1990s, and that, while it benefited from the E.U. integration, it has not yet finished its process of convergence (and if it has, that speaks poorly of the Romanians).
Puerto Rico and its transformation is a really interesting case and speaks much of the economics of imperialism and how might imperialism have progressed had it not disappeared. It will hopefully be dissected more thoroughly in a later post.
What are the causes of the ascent of the second world? The first thing to note is that the Southern Cone did not experience a process of convergence with the U.S. between 1950 and 1980, while Southern Europe, southern Italy, and American Blacks did. Causes include increasing prevalence among the leadership of Southern Europe of support for European (not just NATO) integration, thus leading to positive institutional change, urbanization, rising agricultural productivity resulting in technological unemployment, the adoption of old productive technology by previously long-stagnant countries in a process of acceleration of modernization, the ease of moving people into productive industrial and service sectors at the time, even for partly rural Mexico and Brazil, though not for the already upper-middle-income, highly urbanized, and red-tape filled Southern Cone, institutional changes in the Axis Powers resulting from the Allied occupation, and the decline of First World trade barriers and the rise of the container ship and the automobile. The rise of the automobile and changes in agricultural technology were, perhaps, the most important factors in the rise of Black Americans and of Puerto Rico.