File him in the category underappreciated economists. Does good governance matter for growth? Could there be a more important question for economists? The standard cross-sectional growth tests do not show much of a robust effect. But Johannes, along with co-authors Robert Klitgaard and Kamil Akramov, has a 150-page paper showing that if you take all the relevant heterogeneities into account yes, Adam Smith and Doug North were right after all.
Or do you prefer simple regressions which meet the eyeball test?
Here is the full paper. Here is Johannes’s long paper on South African economic history.