Scholars of the continent of Africa sometimes feel moved to expostulate: "Africa is not a country!" In part, they are reacting against a certain habit of speech and writing where someone discusses, say, the United States, China, Germany, and Africa--although only the first three are countries. More broadly, they are offering a reminder that Africa is a vast place, and that generalizations about "Africa" may apply only to some of the 54 countries in Africa.
Economic research on "Africa" apparently runs some risk of falling into this trap. Obie Porteous has published a working paper that looks at published economics research on Africa: "Research Deserts and Oases: Evidence from 27 Thousand Economics Journal Articles" (September 8, 2020). Porteus creates a database of all articles related to African countries published between 2000-2019 in peer-reviewed economics journals. He points out that the number of such articles has been rising sharply: "[T]he number of articles about Africa published in peer-reviewed economics journals in the 2010s was more than double the number in the 2000s, more than five times the number in the 1990s, and more than twenty times the number in the 1970s." His data shows over 19,000 published economics article about Africa from 2010-2019, and another 8,000-plus from 2000-2010.
But the alert reader will notice how easy, as shown in the previous paragraph, to slip into discussing articles "about Africa." Are economists studying a wide range of countries across the continent, or are they studying relatively few countries. Porteous has some discouraging news here: "45% of all economics journal articles and 65% of articles in the top five economics journals are about five countries accounting for just 16% of the continent's population."
The "frequent 5" five much-studied countries are Kenya, South Africa, Ghana, Uganda, and Malawi. As Porteous points out, it's straightforward to compile the "scarce 7": the seven countries Sudan, D.R. Congo, Angola, Somalia, Guinea, Chad, and South Sudan,with the same population as the frequent 5, but account for only 3.5% of all journal articles and 4.7% of articles in the top 5 journals.
What explains what some countries are common locations for economic research while others are not? Porteous writes: "I show that 91% of the variation in the number of articles across countries can be explained by a peacefulness index, the number of international tourist arrivals, having English as an oﬃcial language, and population." It's certain easier for many economists to do research in English-speaking countries that are peaceful and popular tourist destinations--and that's what has been happening. There's also evidence that even within the highly-researched countries, some geographic areas are more often researched than others.
Of course, it's often useful for a research paper to focus on a specific situation. The hope is that as such papers accumulate, broad-based lessons begin to emerge that can apply beyond the context of a specific country (or area within a country). But local and national context is often highly relevant to the findings of an economic study. It seems that a lot of what economic research has learned about "Africa" is actually about a smallish slice of the continent.