Economic Research per country and US state

Some posts ago I showed a world map of Economic Departments that I made using online software. Today I want to show the next map that occurred to me. (The following map was made using the same software and data source). Here, I split up USA into states and research was worked out using aggregated academic papers' impact. It can be seen that many US state by themselves are ahead of the economic research worldwide.

It would be great to know what variables can explain states/countries amount of research. I guess that GDP may be a basic explanatory variable. So, if we rank all countries by GDP PPP and Economic variables and we plot it, we get the following chart.

Where dots on the black line are countries that are ranked in the same position for GDP and 'Economic Research'. Dots above the black line are doing more economic research than we would expect given their GDP. And the opposite is for dots below the black line. District of Columbia is arguably a special case, but Israel, Switzerland, Connecticut, Missouri, Massachusetts,... are examples of overachievements in economic research giving their income. Japan and Texas are on the underachievement zone.

To be honest, I think this is misleading because countries like China and India which have a huge GDP are basically very poor and therefore we shouldn't expected high economic research from them. Using GDP per capita wouldn't solve the problem because Luxembourg is rich but too small.

So, the following chart only includes the richest countries/states (excluding small states/countries like Distr. of Columbia) and its regression line. Note that axis are no ranks anymore, simply the Ln(GDP ppp) and Economic Research value (the lower the more they research):