<p>There are still schools and school systems that don’t require 4 core courses in all 4 subjects. I would suspect that the IB diplomma is enough. Your son is taking plenty of rigorous courses.</p>
<p>In fact, in our state, economics is the required history for seniors. This year, at least a handful of our students were admitted (and will be attending) Ivies, so I think you have no problem at all. (typical history track here-- civics/geography, world history, American history and then economics.) </p>
<p>Listen to your counselor.</p>