Thanks for the in-depth questions! You’re right, and this is another limitation. Even for cases where there is no inter-wave activism, I should make it clear that the estimates are only truly causal if you adjust for all relevant confounders, which is unlikely in practice. So the results we get are associations, but less biased (aka causal under certain assumptions).
The main way we address this issue is through the sensitivity analysis, since it gives a sense of how much unmeasured confounding is required (from a variable not collected or a variable collected not granularly enough like you pointed out) to overturn significance. In our case, a moderate amount would be needed, so the estimates are likely at least directionally consistent.
Thanks for the in-depth questions! You’re right, and this is another limitation. Even for cases where there is no inter-wave activism, I should make it clear that the estimates are only truly causal if you adjust for all relevant confounders, which is unlikely in practice. So the results we get are associations, but less biased (aka causal under certain assumptions).
The main way we address this issue is through the sensitivity analysis, since it gives a sense of how much unmeasured confounding is required (from a variable not collected or a variable collected not granularly enough like you pointed out) to overturn significance. In our case, a moderate amount would be needed, so the estimates are likely at least directionally consistent.