I've been reading a lot of post-Keynesian material for my Macro Political Economy class (starting Monday), and like any heterodox school the readings have a lot of discussion of history of thought and institutional history. One of the old debates was over aggregation.
One of the striking things is that the fights that post-Keynesians were involved in about this several decades ago (and perhaps that Austrians at that time were involved in too?) were largely over the technical questions around aggregation: can you aggregate meaningfully?
After reading a lot of this, I can't help but feeling like the modern critics of aggregation are a lot more superficial in the more literal sense of the word "superficial" that they're just worried that you miss important sub-aggregate processes when you aggregate that have a story to tell.