## A Curated List of Our Postings on Technical Topics – Your One-Stop Shop for Methodology

*Updated February 17, 2017.*

**Random Assignment**

Allocating treatment and control with multiple applications per applicant and ranked choices [1]

Is optimization just re-randomization redux? Thoughts on the "don't randomize, optimize" papers [2]

Be an optimista, not a randomista, when you have small samples [3]

Tips for randomization in the wild: adding a waitlist [4]

How to randomize in the field [5]

Stratified randomization and the FIFA world cup [6]

Doing stratified randomization with uneven numbers in the Strata [7]

How to randomize using many baseline variables [8]

Public randomization ceremonies [9]

Designing experiments to measure spillover effects [10]

Mechanism experiments [11] and opening up the black box [12]

Sample weights and RCT design [13]

Response to the policymaker complaint that randomized experiments take too much time [14]

Have RCTs taken over development economics? [15]

Definitions in RCTs with interference [16]

**Pre-analysis plans and reporting**

Pre-registration of studies to avoid fishing and allow transparent discovery [17]

A joint test of orthogonality when testing for baseline balance [18]

A pre-analysis plan check-list [19]

The New Trial Registries [20]

What isn’t reported in impact evaluations but maybe should be [21]

Randomization checks: testing for joint orthogonality [18]

An addendum to pre-analysis plans: pre-specifying when not to use data [22]

**Propensity Score Matching**

Guido Imbens on clustering standard errors with matching [23]

Testing different matching estimators as applied to job training programs [24]

The covariate balanced propensity score [25]

**Difference-in-Differences**

The often unspoken assumptions behind diff-in-diff [26]

**Regression Discontinuity**

Curves in all the wrong places: Gelman and Imbens on why not to use higher-order polynomials in RD [27]

Regression discontinuity with an implicit index [28]

Tools of the trade: the regression kink design [29]

**Other Evaluation Methods**

Evaluating an Argentine tourism policy using synthetic controls: tan linda que enamora? [30]

Impact as narrative [31]

The synthetic control method [32], as applied to regulatory reforms

Using spatial variation [33] in program performance to identify impacts

Small n impact evaluation methods [34]

Can we trust shoestring evaluations? [35]

Using case studies to explore and explain complex interventions [36]

**Analysis**

Another reason to prefer Ancova: dealing with measurement changes between baseline and follow-up [37]

Endogenous stratification: the surprisingly easy way to bias your heterogeneous treatment effects and what to do instead [38]

Why is difference-in-difference estimation still so popular in experimental analysis? [39]

Regression adjustment in randomized experiments (part one [40], part two [41])

When to use survey weights [42] in analysis

Adjustments for multiple hypothesis testing [43]

Bounding approaches to deal with attrition [44]

Linear probability models versus probits [45]

Dealing with multiple lotteries [46]

Estimating standard errors with small clusters (part one [47], part two [48])

Decomposition methods [49]

Estimation of treatment effects with incomplete compliance [50]

What does Alwyn Young's paper mean for analysis of experiments? [51]

Winsorizing, testing balance, and dealing with incomplete take-up [52]

You ran a field experiment, should you then run a regression? [53]

**Power Calculations and Improving Power**

Should I work with only a subsample of my control group if I have take-up problems? [54]

Power calculations: what software should I use? [55]

Does the intra-cluster correlation matter for power calculations if I am going to cluster my standard errors? [56]

Power calculations for propensity score matching [57]

Power calculations 101: dealing with incomplete take-up [58]

Collecting more rounds of data to boost power [59]

Improving power in small samples [60]

Did you do your power calculations using standard deviations? Do them again. [61]

Power calculations for regression discontinuity (part 1 [62], part 2 [63], part 3 [64])

Power calculation software for randomized saturation experiments [65]

**On External Validity**

Getting beyond the mirage of external validity [66]

All those external validity issues with impacts? They apply to costs too [67]

External validity as seen from other quantitative social sciences and the gaps in our practices [68]

Towards a more systematic approach to external validity: understanding site selection bias [69]

Weighting for external validity [70]

Will that successful intervention over there get results here? [71]

Learn to live without external validity [72]

Why the external validity of regression estimates can be less than you think [73]

Why similarity is the wrong concept for external validity [74]

A rant on the external validity double standard [75]

Towards policy irrelevance: on the experimental arms race [76]

What's wrong in how we do impact evaluation? [77]

What's in a title? Signaling external validity through titles in development economics [78]

**Jargony Terms in Impact Evaluations**

A proposed taxonomy of behavioral responses to evaluation [79]

Quantifying the Hawthorne effect [80]

The Hawthorne Effect [81]

The John Henry Effect [82]

Placebo effects [83]

Clinical Equipoise [84]

**Stata Tricks**

Generating regression and summary statistics tables in Stata [85]

Graphing impacts with Standard Error Bars [86]

Calculating the intra-cluster correlation [87]

Generating regression and summary statistics tables in Stata: A checklist and code [85]

**Replication**

Worm wars: the anthology [88]

Worm wars: a review of the reanalysis of the Miguel and Kremer deworming study [89]

Response to Brown and Wood's response [90]

Brown and Woods response on "how scientific are scientific replications" [91]

how scientific are scientific replications? [92]

The infinite loop of failure of replication in economics [93]

More replication in economics [94]

**Systematic reviews and meta-analysis**

how systematic is that systematic review? The case of learning outcomes [95]

How standard is a standard deviation? A cautionary note on using SDs to compare across impact evaluations [96]

should we give up on SDs for measuring effect size? [97]

What do 600 papers on 20 types of interventions tell us about what types of interventions generalize? [98]

If you want your study included in a systematic review, this is what you should report [99]

**Book Reviews for Books on Impact Evaluation**

Review of Imbens and Rubin's Causal Inference [100]

Review of Glennerster and Takavarasha's Running Randomized Experiments [101]

Review of Gerber and Green's Field Experiments [102]

Review of Karlan and Appel's Failing in the Field [103]

Review of Tim Ogden's Experiments in Development from Every Angle [104]

**Getting Published**

11 tips for making a short presentation based on your research [105]

- Tags:
- Difference-in-difference [106]
- statistical power [107]
- propensity score [108]
- external validity [109]
- randomization [110]
- Life the Universe and Everything [111]