As a practicing economist, I wonder what use cases you're referring
to. I can't think of any use cases where if one previous value is
useful, having all previous values available (ie, an arbitrary
temporal structure, at the modeler's option) isn't vastly more useful.
So in the end, even if there are plausible use cases for quick and dirty code, [...]
There was a discussion about this a while ago.
[...]. From what
I remember, the conclusion reached was that there are too
many degrees of freedom to be able to express reduction
operations in a comprehension-like way that's any clearer
[...] you better have a VERY GOOD reason.