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


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This is a curated list of our technical postings, to serve as a one-stop shop for your technical reading. I’ve focused here on our posts on methodological issues in impact evaluation – we also have a whole lot of posts on how to conduct surveys and measure certain concepts curated here. In lieu of our regular links this week, it is updated up to October 25, 2018
IEanalytics: introducing the Development Impact Evaluation wiki
Random Assignment
Allocating treatment and control with multiple applications per applicant and ranked choices
Is optimization just re-randomization redux? Thoughts on the "don't randomize, optimize" papers
Be an optimista, not a randomista, when you have small samples
Tips for randomization in the wild: adding a waitlist
How to randomize in the field
Stratified randomization and the FIFA world cup
Doing stratified randomization with uneven numbers in the Strata
How to randomize using many baseline variables
Public randomization ceremonies
Designing experiments to measure spillover effects
Mechanism experiments and opening up the black box
Sample weights and RCT design
Response to the policymaker complaint that randomized experiments take too much time
Have RCTs taken over development economics?
Definitions in RCTs with interference
What does a game-theoretic model with belief-dependent preferences teach us about how to randomize?
Incorporating participant welfare and ethics into RCTs
Are we over-investing in baselines?
Most good you can do, but for whom? (on spillovers)
Pre-analysis plans and reporting
Pre-registration of studies to avoid fishing and allow transparent discovery
A joint test of orthogonality when testing for baseline balance
A pre-analysis plan check-list
The New Trial Registries
What isn’t reported in impact evaluations but maybe should be
Randomization checks: testing for joint orthogonality
An addendum to pre-analysis plans: pre-specifying when not to use data
A pre-analysis plan is the only way to take your p-values seriously
Trouble with pre-analysis plans? try these 3 weird tricks
Should we require balance t-tests on observables with randomized experiments?
Registered reports: piloting a pre-results review process at the JDE
Declaring and diagnosing research designs
Propensity Score Matching
Guido Imbens on clustering standard errors with matching
Testing different matching estimators as applied to job training programs
The covariate balanced propensity score
The often unspoken assumptions behind diff-in-diff
How big data helped us estimate the impact of an intervention with 0.8% take-up

What are we estimating when we estimate DiD (Goodman-Bacon decomposition)

Revisiting the DiD parallel trends assumption part I

Revisiting the Difference-in-Differences parallel trends assumption part II

Regression Discontinuity
Curves in all the wrong places: Gelman and Imbens on why not to use higher-order polynomials in RD
Regression discontinuity with an implicit index
Tools of the trade: the regression kink design
Synthetic Controls
Evaluating an Argentine tourism policy using synthetic controls: tan linda que enamora?
The synthetic control method, as applied to regulatory reforms
Instrumental Variables
Rethinking identification under the Bartik/Shift-Share instruments
Judge leniency designs: Now not just for Crime Studies
Machine learning
How can machine learning and artificial intelligence be used in development interventions and analysis?
Other Evaluation Methods
Impact as narrative
Using spatial variation in program performance to identify impacts
Small n impact evaluation methods
Can we trust shoestring evaluations?
Using case studies to explore and explain complex interventions
Another reason to prefer Ancova: dealing with measurement changes between baseline and follow-up
Endogenous stratification: the surprisingly easy way to bias your heterogeneous treatment effects and what to do instead
Why is difference-in-difference estimation still so popular in experimental analysis?
Regression adjustment in randomized experiments (part one, part two)
When to use survey weights in analysis
Adjustments for multiple hypothesis testing
Bounding approaches to deal with attrition
Linear probability models versus probits
Dealing with multiple lotteries
Estimating standard errors with small clusters (part one, part two)
Decomposition methods
Estimation of treatment effects with incomplete compliance
What does Alwyn Young's paper mean for analysis of experiments?
Winsorizing, testing balance, and dealing with incomplete take-up
You ran a field experiment, should you then run a regression?
Sometimes, increasingly, estimating the ITT is not enough in experiments
Finally an easy way to do randomization inference in Stata
When should you cluster standard errors? New wisdom from the econometrics oracle
Your go to regression specification is biased: here is the simple fix
What should you do when your random assignment gets compromised?
Power Calculations and Improving Power
Should I work with only a subsample of my control group if I have take-up problems?
Power calculations: what software should I use?
Does the intra-cluster correlation matter for power calculations if I am going to cluster my standard errors?
Power calculations for propensity score matching
Power calculations 101: dealing with incomplete take-up
Collecting more rounds of data to boost power
Improving power in small samples
Did you do your power calculations using standard deviations? Do them again.
Power calculations for regression discontinuity (part 1, part 2, part 3)
Power calculation software for randomized saturation experiments
Statistical power and the funnel of attribution
Should you over-sample compliers if budget is limited and you are concerned about take-up?
On External Validity
Getting beyond the mirage of external validity
All those external validity issues with impacts? They apply to costs too
External validity as seen from other quantitative social sciences and the gaps in our practices
Towards a more systematic approach to external validity: understanding site selection bias
Weighting for external validity
Will that successful intervention over there get results here?
Learn to live without external validity
Why the external validity of regression estimates can be less than you think
Why similarity is the wrong concept for external validity
A rant on the external validity double standard
Towards policy irrelevance: on the experimental arms race
What's wrong in how we do impact evaluation?
What's in a title? Signaling external validity through titles in development economics
A framework for taking evidence from one setting to another
Informing policy with research that is more than the sum of the parts
Jargony Terms in Impact Evaluations
A proposed taxonomy of behavioral responses to evaluation
Quantifying the Hawthorne effect
The Hawthorne Effect
The John Henry Effect
Placebo effects
Clinical Equipoise
Social Desirability Bias/Experimenter Demand Effects and more on Experimenter Demand Effects
Stata Tricks
Generating regression and summary statistics tables in Stata
Graphing impacts with Standard Error Bars
Calculating the intra-cluster correlation
Generating regression and summary statistics tables in Stata: A checklist and code
Stata code for correlated random coefficient models
Finally an easy way to do randomization inference in Stata
IEanalytics: introducing ietoolkit
Five small things I've learned recently
Worm wars: the anthology
Worm wars: a review of the reanalysis of the Miguel and Kremer deworming study
Response to Brown and Wood's response
Brown and Woods response on "how scientific are scientific replications"
how scientific are scientific replications?
The infinite loop of failure of replication in economics
More replication in economics
A cynic's take on papers with novel methods to improve transparency
Systematic reviews and meta-analysis
how systematic is that systematic review? The case of learning outcomes
How standard is a standard deviation? A cautionary note on using SDs to compare across impact evaluations
should we give up on SDs for measuring effect size?
What do 600 papers on 20 types of interventions tell us about what types of interventions generalize?
If you want your study included in a systematic review, this is what you should report

Book Reviews for Books on Impact Evaluation
Review of Banerjee and Duflo's Poor Economics (and authors' reply)
Review of Manzi's Uncontrolled
Review of Imbens and Rubin's Causal Inference
Review of Glennerster and Takavarasha's Running Randomized Experiments
Review of Gerber and Green's Field Experiments
Review of Karlan and Appel's Failing in the Field
Review of Ogden's Experiments in Development from Every Angle
Review of Leigh's Randomistas: how radical researchers changed the world
Review of Gugerty and Karlan's The Goldilocks Challenge: Right-fit evidence for the social sector

Getting Published
11 tips for making a short presentation based on your research
State of Development Journals 2017
10 journals for publishing a short economics paper
How to publish statistically insignificant results in development
The State of Development Journals 2018
Writing a papers and proceedings paper
Have descriptive development papers been crowded out by impact evaluations?
Make your research known - 10 tools for increasing consumption of your research


David McKenzie

Lead Economist, Development Research Group, World Bank

March 31, 2014

I wish that other bloggers would do something like this. It is always nice to have a mini "database" of articles about a certain topic. You never know when something like that will come in handy.

October 12, 2015

How is this "curated" exactly? It's just a freaking list. Stop saying things are "curated." You can't "curate" a list of things you already published. I'd contend you can't "curate" a list of anything at all. What an obnoxious trend it is becoming to use the word "curated" for "a bunch of stuff a person happens to like." Ugh!

David McKenzie
October 13, 2015

Curate, verb meaning to select, organize, and look after the items in a collection. This precisely describes the process used to go through almost 5 years of old blog posts, select the ones related to technical topics, and organize them in a way that is hopefully useful for people so that they form a coherent collection.

D Phillips
September 29, 2015

David - I defer absolutely to the high level of sophistication of your impact benefits analysis (!) - i.e. the calculation of the numerator of your rate of return. However I could not get a good understanding of the cost - i.e. the denominator. I.e. what is the (social) cost of the impact benefits.
If we don't take the cost into account then we of course we might be saying simply that if you give an entrepreneur $50,000 his business is likely to be in better shape in three years time than one that does not get the $50,000 under most scenarios - which would not be surprising.
Please could you explain What is the denominator?
1. just the value of the business grants?
2. 1. plus BPC management costs?
3. 2. plus transaction costs to winning (and losing) entrepreneurs?
4. 3. plus matching investment from the entrepreneur?
5. 4. plus contributed investment funds (funded by outside loans, equity)?
And if it is 1. or 2. how much of the overall return benefits are attributable only to the grants? Could we assume a crowding-in effect which attributes the complementary investment also to some extent to the grants ?? (I see that you have found no crowding in effect overall but it seems likely to have happened in some cases).
Getting back to the numerator how have you accounted for benefit externalities that might show up in linkages and associated technological spillover effects, which are arguably key to the development of industry, banking and business services etc? (That is, indirect effects that cannot be accounted for through performance of the treatment or control group enterprises). OR how do you allow for possible contamination of the control group by technological spillovers generated by enterprises that receive awards?? (Apart from the fact hat Nigeria ia a big country and businesses may not meet face to face).
Id really appreciate understanding this since it is key to the validity of the rate of return analysis and by extension the value of business plans.

David McKenzie
September 29, 2015

This should really be posted as a comment to my post on the Nigeria business plan competition, not to the general technical topic links. But I couldn't figure out how to move where you had put the comment, so will answer here.
Short answer is that:
- the measures of impact take into account transaction costs to the winners, and any crowding out or crowding in of other funding, including matching funding provided by them and/or equity/loan finance that is crowded out. The paper shows a little bit of crowd-out of this other finance, and no evidence of crowding in.
- I am not able to measure the spillovers to the control group, and have to rely on it being a small number of winners spread throughout the country.
- the measure of the cost of the program includes both the cost of the grants and the cost of operating the program (approx $2 million in costs to hand out $58 million in grants).

August 30, 2015

Great list - knew many of these posts but not others, great to have them all together in one place. Now David, a follow-up request. I knew your small N larg T paper and its ANCOVA recommendation, but I hadn't seen the posts by Lin on regression adjustment:
A linear combination of both would be great, since "your" ANCOVA is a regrssion adjustment on a special case, averaged pre-treatment outcomes, and those may vary substantially with the outcomes and the treatment effects...

Gaurav D. Joshi
August 24, 2015

Fully Agree with Homira. Thanks a ton David for showing the way. Hope other interesting topics will also have one such 'one-stop-shop'.

Homira Nassery
August 21, 2015

Truly outstanding knowledge management.

Barbara Bitondo
February 10, 2018

I’d welcome the Feb 2018 edition of this list!