Finally, there is a rich branch of the literature concerned with effect estimation, and which is strongly rooted in the field of causality. Especially if some of the non-meteorological variables can be intervened upon (e.g., via policies), direct and total effects can be estimated (see, e.g., ). Indeed, intervening on the non-meteorological variable by setting it to T = t (e.g., via a policy) but keeping the meteorological variables unaffected leads to the definition of the average natural direct 265 effect . Note that the direct effect is related to the response due to direct influence of T , which we denoted as y direct (t) in our work; the quantity E Y ∼p Y |t [Y ], and hence the results M (t) of meteorological normalization, is thus related to the total effect. Future work shall investigate these connections in deeper details and explore approaches how meteorological normalization could benefit from this perspective of effect estimation rooted in causal theory.