Causal Catalog#

Assumptions#

Consistency#

Definition

The observed outcome \(Y\) for a unit is the same as the potential outcome \(Y(T=t)\) for that unit under the treatment that was actually observed \(T=t\).

Mathematical definition

\(Y = Y(T)\)

For binary treatment, that means:

  • \(Y = Y(1) \text{ if } T=1\)
  • \(Y = Y(0) \text{ if } T=0\)

Intuition/Examples

Expired aspirin (Lecture 2, slide 31)
High or low energy dog (Neal reading, p14)

Exchangeability#

Definition

The distribution of \(Y(0)\) and \(Y(1)\) for the \(T=1\) and \(T=0\) groups are the same. Also known as ignorability.

Mathematical definition

\(Y(0), Y(1) \perp T\)

Intuition/Examples

Caffeine and exam performance brainstorm

Study Designs#

Randomized Experiments#

Assumptions needed

  • Consistency
  • No interference

Assumptions ensured

  • Exchangeability

Causal quantities identified

Average treatment effect (ATE)

Pros/cons#

Advantages

Disadvantages

To be added after our brainstorming!