Is it possible for two equally rich countries (on a per capita basis) to have different level of output per worker? The answer is obviously yes, and it matters in the case of measuring growth in Cuba since the revolution.
A country with a very young population will tend to have fewer workers than one with an older (but not too old) population. Let’s say that countries A and B have a median age of 22.5 in year one. However, in year ten, country A has a median age of 35 but country B has seen a more modest increase to a median age of 25. This will bias any estimates of growth comparison between both country. The increase in the median age suggests that there are more and more workers in country A (people of prime age) than in country B. As a result of that, output per capita will increase faster in country A than in country B even if both countries have equal rates of growth in output per worker.
Well, countries A and B are basically Cuba and most of the rest of Latin America. Since the 1950s, Cuba’s population has aged rapidly but birth rates have plummeted so fast that families shrunk. With fewer kids in the population, it means that the share of the Cuban population that are of prime working age increased rapidly. This is what biases the comparison of Cuban living standards with other Latin American countries.
In the figure below, I took the GDP (the Maddison data) of Cuba since 1950 (indexed at 1960 to see the arrival of Castro) and divided it by the total population, the population above 15 years of age and the population between 15 and 64.
As one can see, with the GDP per capita series, Cubans saw a 50% increase in their incomes between 1960 and 2005 (the Maddison data stops at 2008). However, when you look at GDP per working age adult in order to capture the growth in productive capacity, you get moderately different results whereby the cumulative increase is three-fifths to half as small.
In light of this, it seems like Cuba’s living standards are less and less impressive.