Skip to content

Commit

Permalink
More work
Browse files Browse the repository at this point in the history
  • Loading branch information
jwbowers committed Apr 8, 2019
1 parent ddfd41f commit 59ed91a
Show file tree
Hide file tree
Showing 2 changed files with 23 additions and 22 deletions.
45 changes: 23 additions & 22 deletions Presentations/causality.Rmd
Original file line number Diff line number Diff line change
Expand Up @@ -159,36 +159,40 @@ key features of two designs --- one observational and the other randomized.

**Possible research questions:**

- Can edutainment (like the Hausa TV Station or radio programs currently being used in Niger) can change attitudes about violence and extermism?
- Does telling low-SES parents about the number of words they speak to their infants and toddlers improve early language aquisition in this group (reducing inequality in early verbal skills and eventually reducing inequality in school readiness at age 5)?
- Can edutainment (like the Hausa TV Station or radio programs currently
being used in Niger) change attitudes about violence and extermism?
(Goal: Reduce violence and extremism.)
- Does information about words spoken to infants/toddlers improve early
language aquisition in this group? (Goal: reduce inequality in early verbal
skills and eventually reducing inequality in school readiness at age 5)

## Exercise: Observational studies vs. Randomized studies

**Tasks:**
1. Sketch an ideal observational study design? (no
randomization, no researcher control but infinite resources for data
collection) What questions would critical readers ask when you claim that your
results reflect a causal relationship?
2. Sketch an ideal experimental study design? (including
randomization and control) What questions would critical readers ask when you claim that your
results reflect a causal relationship?

1. Sketch an ideal observational study design? (no randomization, no
researcher control but infinite resources for data collection) What
questions would critical readers ask when you claim that your results
reflect a causal relationship?

2. Sketch an ideal experimental study design? (including randomization and
control) What questions would critical readers ask when you claim that
your results reflect a causal relationship?

## Why randomize?

Randomization produces \textbf{fair} comparisons (ex. impersonal, no
systematic differences between groups).
1. Randomization produces \textbf{fair} comparisons (ex. impersonal, no
systematic differences between groups).

Randomization helps us reason about information/uncertainty.
2. Randomization helps us reason about information/uncertainty.

> "Fisher realized that an uncertain answer to the right question is much better than a highly certain answer to the wrong question...If you ask the right question, getting an answer that is occasionally wrong is much less of a problem [than answers to the wrong question]. You can still estimate the amount of uncertainty in your answer, because the uncertainty comes from the randomization procedure (which is known) rather than the characteristics of the soil (which are unknown)." \citep{pearl2018book}

# Overview of Statistical Inference for Causal Quantities

## Counterfactual Causal \textcolor{orange}{Inference}}
## Using randomization to reason about causal \textcolor{orange}{Inference}

How can we use what we \textbf{see} to learn about \only<1>{what we want to
\textbf{know}} \only<2->{\textbf{potential outcomes} ($\text{causal effect}_i=f(y_{i,1},y_{i,0})$})?
\textbf{know}} \only<2->{\textbf{potential outcomes} ($\text{causal effect}_i=f(y_{i,1},y_{i,0})$}?


```{r readdata, echo=FALSE}
Expand Down Expand Up @@ -216,10 +220,11 @@ newspapers.xtab<-xtable(newsdf[,c("city","s","z","rpre","r","Newspaper","y1","y0
```{r newsdesigntab,results='asis',echo=FALSE}
print(newspapers.xtab,
sanitize.text.function=function(x){x},include.rownames=FALSE,include.colnames=FALSE,
table.placement="!ht",##size="small",
table.placement="!ht",size="small",
comment=FALSE,
add.to.row=list(pos=list(-1),
command="&&& \\multicolumn{2}{c}{Turnout} \\\\ City &
Pair & Treatment & \\multicolumn{1}{c}{Baseline} &
Pair & Treat & \\multicolumn{1}{c}{Baseline} &
\\multicolumn{1}{c}{Outcome} &
\\multicolumn{1}{c}{Newspaper} &
\\multicolumn{1}{c}{$y_{1}$} &
Expand Down Expand Up @@ -290,10 +295,6 @@ mean(thedist >= theobs)
\only<1->{For the sharp null test: Randomization occurred as
reported.}

%% INCLUDE SLIDE FROM YALE TALK ON INTERFERENCE AND SHARP NULL

\medskip

\only<2->{For the average treatment effect: Randomization occurred
as reported plus no interference between units.}

Expand Down
Binary file modified Presentations/causality.pdf
Binary file not shown.

0 comments on commit 59ed91a

Please sign in to comment.