The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 1

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 2

What is: E [ Y | D = 1] ?

 

Is it observable?

The expected value of the outcome Y given that treatment 1 was received.  If some of the units received treatment 0 then we cannot observe this.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 3

What is: E [ Y1 ] ?

 

Is it observable?

The expected value of the outcome Y given that treatment 1 was received.  If some of the units received treatment 0 then we cannot observe this.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 4

What is: E [ Y | D = 0]?

 

Is it observable?

The expected value of the outcome Y given that treatment 0 was received.  If some of the units received treatment 1 then we cannot observe this.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 5

What is: E [ Y0 ] ?

 

Is it observable?

The expected value of the outcome Y given that treatment 0 was received.  If some of the units received treatment 1 then we cannot observe this.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 6

RECAP:

 

E [ Y0 ]           E [ Y1 ]           E [ Y | D = 0]           E [ Y | D = 1]

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 7

What is:   E [ Y | D = 1]  -  E [ Y | D = 0] ?

 

Is it observable?

The expected value of the  Y given that treatment 1 was received minus the expected value of the outcome given that treatment 0 was received. This is the true treatment effect. It is not observable.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 8

What is:   E [ Y0 | D = 0]?

 

Is it observable?

The expected value of the outcome Y after treatment 0 given that treatment 0 was received.  These are the control group cases and they can be observed.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 9

What is:   E [ Y1 | D = 1]?

 

Is it observable?

The expected value of the outcome Y after treatment 1 given that treatment 1 was received.  These are the treatment group cases and they can be observed.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 10

What is:   E [ Y0 | D = 1]?

 

Is it observable?

The expected value of the outcome Y after treatment 0 given that treatment 1 was received.  These are imaginary cases and they cannot be observed.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 11

What is:   E [ Y1 | D = 0]?

 

Is it observable?

The expected value of the outcome Y after treatment 1 given that treatment 0 was received.  These are imaginary cases and they cannot be observed.

ICS212 Fall 2022

The simple case of a treatment group (D = 1), and a control group (D = 0).

One outcome Y.

Potential outcome after receiving treatment 0: Y0

Potential outcome after receiving treatment 1: Y1

simplified notation.pdf - 12

What is:   E [ Y0 | D = 1] - E [ Y0 | D = 0]?

 

Is it observable?

The difference between the expected outcome for the treatment group had they not been treated and the expected outcomes of the control group. This is not observable

ICS212 Fall 2022