Does this explain the fact that this pattern didn’t show up in the not-for-profit schools until much later? I’m not against the idea that govt subsidies raise

Does this explain the fact that this pattern didn’t show up in the not-for-profit schools until much later? I’m not against the idea that govt subsidies raise prices, but it seems like cherry picking to fit a shaky model.[1] If it’s a primary factor, wouldn’t we see that across all schools? Perhaps there’s a different, more foundational cause and we’re being fooled by spurious correlation. If it isn’t applicable elsewhere I fail to see how it can be labeled a root cause. [1]For example, UofPhoenix was not founded until the late 1970s. This also corresponds to a handful of other societal factors can can be argued contributed to educational costs. If the GI Bill was primarily driving these costs, we should see it in the way the benefits were implemented. Like a high spike post WW2, to waning post Vietnam, to slightly higher with the Montgomery GI bill, to another spike with the post 9/11 GI Bill. But college tuition costs seem to be a fairly steady march higher, including not-for-profit non-vocational schools.