class: center middle main-title section-title-3 # In-person<br>session 9 .class-info[ **March 10, 2022** .light[PMAP 8521: Program evaluation<br> Andrew Young School of Policy Studies ] ] --- name: outline class: title title-inv-8 # Plan for today -- .box-3.medium[General questions] -- .box-7.medium[Final project] -- .box-1.medium[Simple diff-in-diff] -- .box-6.medium[Two-way fixed effects] -- .box-2.medium[Sensitivity analysis] --- layout: false name: general-questions class: center middle section-title section-title-3 animated fadeIn # General questions --- class: middle .box-3.large[Should we control for variables<br>to close as many backdoors as<br>possible in our diff-in-diff model?] --- class: title title-3 # Design-based identification .box-inv-3[Use a special situation to isolate arrow] .pull-left[ .box-3[RCTs] .box-inv-3.small[Use randomization<br>to remove confounding] .center[ <figure> <img src="05-slides_files/figure-html/experimental-dag-1.png" alt="RCT DAG" title="RCT DAG" width="60%"> </figure> ] ] -- .pull-right[ .box-3[Difference-in-differences] .box-inv-3.small[Use before/after & treatment/control<br>differences to remove confounding] .center[ <figure> <img src="08-slides_files/figure-html/min-wage-dag-1.png" alt="Diff-in-diff DAG" title="Diff-in-diff DAG" width="90%"> </figure> ] ] --- layout: true class: middle --- .box-3.large[How does moving time back<br>let us check for parallel trends?]' --- .center[ <figure> <img src="img/08-class/mm-fig-5-4.png" alt="Mastering Metrics Figure 5.4" title="Mastering Metrics Figure 5.4" width="65%"> </figure> ] --- .box-3.large[Can you conduct diff-in-diff<br>with a binary outcome?] --- .box-3.large[I keep reading about estimates, estimands, and estimators.<br>What are these and are they the same thing?] --- layout: false class: title title-3 # Estima(and|or|ate)s .box-inv-3.less-medium[Estimand] .box-3.sp-after[Theoretical thing you want to know (β)] .box-inv-3.less-medium[Estimator] .box-3.sp-after[Process for guessing the thing .small[(e.g., diff-in-diff with interaction term)]] .box-inv-3.less-medium[Estimate] .box-3[The guess (β-hat)] --- class: middle .center[ <figure> <img src="img/09-class/estimandateor.jpg" alt="Estimandateor" title="Estimandateor" width="45%"> </figure> ] ??? <https://twitter.com/WomenInStat/status/1449068312873287682> --- class: middle .center[ <figure> <img src="img/09-class/estimands-methods.png" alt="Estimand methods" title="Estimand methods" width="75%"> </figure> ] ??? <https://arxiv.org/abs/2106.10577> --- class: middle .center[ <figure> <img src="img/09-class/flowchart.png" alt="Estimand flowchart" title="Estimand flowchart" width="100%"> </figure> ] --- class: middle .center[ <figure> <img src="img/09-class/three-step-process.png" alt="Three-step process" title="Three-step process" width="75%"> </figure> ] --- layout: false name: final-project class: center middle section-title section-title-7 animated fadeIn # Final project --- class: middle .box-7.large[Tell us more about<br>the final project!] --- layout: false name: diff-in-diff class: center middle section-title section-title-1 animated fadeIn # Simple diff-in-diff --- layout: true class: middle --- .box-1.large[Minimum legal drinking age] --- .box-inv-1.medium[MLDA reduction] .box-1.medium[Two states: Alabama vs. Arkansas] `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \beta_3\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` --- .box-inv-1.medium[Organ donations] .box-1.medium[Two states: California vs. New Jersey] `$$\begin{aligned} \text{Donation rate}\ =&\ \beta_0 + \beta_1\ \text{California} + \beta_2\ \text{After Q22011}\ + \\ &\ \beta_3\ (\text{California} \times \text{After Q22011}) \end{aligned}$$` --- layout: false name: twfe class: center middle section-title section-title-6 animated fadeIn # Two-way fixed effects<br>(TWFE) --- layout: true class: middle --- .box-6.medium[Two states: Alabama vs. Arkansas] `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \beta_3\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` --- .box-6.medium[All states: `Treatment == 1`<br>if legal for 18-20-year-olds to drink] `$$\text{Mortality}\ =\ \beta_0 + \beta_1\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}$$` --- `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \color{red}{\beta_3}\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` .center[vs.] `$$\text{Mortality}\ =\ \beta_0 + \color{red}{\beta_1}\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}$$` --- `$$\begin{aligned} \text{Mortality}\ =&\ \beta_0 + \beta_1\ \text{Alabama} + \beta_2\ \text{After 1975}\ + \\ &\ \color{red}{\beta_3}\ (\text{Alabama} \times \text{After 1975}) \end{aligned}$$` .center[vs.] `$$\text{Mortality}\ =\ \beta_0 + \color{red}{\beta_1}\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}$$` .center[vs.] `$$\begin{aligned} \text{Mortality}\ =\ & \beta_0 + \color{red}{\beta_1}\ \text{Treatment} + \beta_2\ \text{State} + \beta_3\ \text{Year}\ +\\ &\beta_4\ (\text{State} \times \text{Year}) \end{aligned}$$` --- .center[ <figure> <img src="img/08-class/mm-tbl-5-2.png" alt="Mastering Metrics Table 5.2" title="Mastering Metrics Table 5.2" width="55%"> </figure> ] --- `$$\begin{aligned} \text{Donation rate}\ =&\ \beta_0 + \beta_1\ \text{California} + \beta_2\ \text{After Q22011}\ + \\ &\ \color{red}{\beta_3}\ (\text{California} \times \text{After Q22011}) \end{aligned}$$` .center[vs.] $$ `\begin{aligned} \text{Donation rate}\ =\ & \beta_0 + \color{red}{\beta_1}\ \text{Treatment}\ + \\ & \beta_2\ \text{State} + \beta_3\ \text{Quarter} \end{aligned}` $$ --- .box-6.large[What about this<br>staggered treatment stuff?] .box-inv-6[[See this](https://www.andrewheiss.com/blog/2021/08/25/twfe-diagnostics/)] ??? This is good for ethical reasons! Blog post --- .box-6.large[What are random effects?] .box-inv-6[[See this](https://www.andrewheiss.com/blog/2021/12/01/multilevel-models-panel-data-guide/)] --- layout: false name: sensitivity class: center middle section-title section-title-2 animated fadeIn # Sensitivity analysis --- layout: true class: middle --- .box-2.medium.sp-after[How do we know when we've got<br>the right confounders in our DAG?] .box-2.medium[How do we solve the fact that<br>we have so many unknowns in our DAG?] --- .center[ <figure> <img src="img/08-class/2020-2021-meme-garnick-1.jpg" alt="OVB" title="OVB" width="40%"> </figure> ] ??? https://owenozier.github.io/teaching/2020-2021-memes