2
$\begingroup$

I am new on the causality topic, I don't know the difference between the average treatment effect and counterfactual mean. Can anyone tell me?

$\endgroup$
4
$\begingroup$

Average treatment effect (ATE)

The average treatment effect (ATE) is a measure used to compare treatments (or interventions) in randomized experiments or observational studies. The ATE is the population mean of (hypothetical) outcomes should everyone receive treatment less the population mean of (hypothetical) outcomes should no-one receive treatment: $$ \text{ATE}=\mathbb{E}(\delta_i)=\mathbb{E}\!\left(Y_i^1-Y_i^0\right)=\mathbb{E}\!\left(Y_i^1\right)-\mathbb{E}\!\left(Y_i^0\right) $$ where $\delta_i$ is the treatment effect for individual $i$, $Y_i^1$ is the outcome for individual $i$ under treatment and $Y_i^0$ is the outcome for individual $i$ under no treatment. (Based on Cunningham (2018) p. 87 and Wikipedia.)

Counterfactual mean

According to Hernán & Robins (2015), counterfactural means are simply the two means defining the ATE, $\mathbb{E}\!\left(Y_i^1\right)$ and $\mathbb{E}\!\left(Y_i^0\right)$; i.e., the population mean of (hypothetical) outcomes should everyone receive treatment and the population mean of (hypothetical) outcomes should no-one receive treatment, respectively.

References

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.