Executive summary: Questions on economic geography can be on-topic, but usually aren't. To be on-topic here, the question should focus on the Earth Science part of the bigger question.
When I had geography in secondary school, the topic was divided in two topics. Somewhat simplified:
- Physical geography, where we used natural sciences to learn about volcanoes, glaciers, and other topics of the Earth Sciences.
- Social geography, where we used sociology, economics, history, to learn about why wars are where they are.
It was not until much later that I appreciated how geography links the two, even though the title of my primary school geography textbook was a giant hint: Waarom daar? or Why there?. To understand why farmers in some parts of The Netherlands have chicken and not crops, you need to consider the Würm glaciation. In the USA, elections are impacted by a 100 million year old coastline.
There are very interesting questions.
I don't think they are in scope within Earth Science.
We need Earth Science to consider those geography questions, just like how we need physics, chemistry, and mathematics to answer Earth Science questions. But that is not enough to make those questions on-topic. Often, geography questions need to consider other factors that are not related to Earth Science. Some examples:
- Why is there a strip of Democratic voting counties surrounded by overwhelmingly Republican voting areas? — the answer dives into the history of Earth, but the question is off-topic on Earth Science. The answer also involves the history of agriculture, slavery, and American politics. We don't have that expertise on this site.
- This strip is good for cotton agriculture and therefore is now home to many slave descendants, but what conditions make it good for growing cotton? — although put in the same context, the question is explicitly about the Earth Science aspect, and is on-topic (minus the biology of the cotton plant).
- Why is the pattern of ditches different in different parts of The Netherlands? — the answer is a combination of natural and human history, delves into fens and bogs but also into the history socio-economic conditions of the humans exploiting the land. We don't have that expertise as Earth Scientists.
- What are some characteristic differences between fens and raised bogs? — this would be the Earth Science part of the question to answer the previous one, and here Earth Science does have the expertise, so this question would be on-topic (although perhaps not very well researched).
- What causes the stark vertical divide in population maps of the United States? — the answer involves climate, but also the history of how the United States was settled (I note there are currently two votes to reopen on the question on History.SE)
- Why is the western half of the USA so much drier than the eastern half? — an important part of the answer to the previous question, and one we can answer on Earth Science. It's not the best question we've seen, but it'd be on-topic.
The critical question is: can we as Earth Scientists offer a complete answer? Then it's on-topic. Or can Earth Science only get toward part of the answer, and would we need the expertise from social sciences to answer the question completely? Then it's off-topic.