power calculations
http://blogs.worldbank.org/impactevaluations/taxonomy/term/4106/all
enPower calculations: what software should I use?
http://blogs.worldbank.org/impactevaluations/power-calculations-what-software-should-i-use
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>
In my experimental work, I almost always do cluster-randomized field experiments (CRTs – T for trials), and therefore I always used the <a href="http://sitemaker.umich.edu/group-based/optimal_design_software" rel="nofollow">Optimal Design software</a> (OD for short), which is freely available and fairly easy to use with menu based dialogue boxes, graphs, etc. However, preparing some materials for a course with a couple of colleagues, I came to realize that it has some strange basic limitations. That led me to invest some time into finding out about my alternatives in Stata. I thought I’d share a couple of things I learned here.</p>
</div></div></div>Mon, 29 Jun 2015 16:17:00 +0000Berk Ozler1281 at http://blogs.worldbank.org/impactevaluationsNotes from the AEAs: Present bias 20 years on + Should we give up on S.D.s for Effect Size?
http://blogs.worldbank.org/impactevaluations/notes-aeas-present-bias-20-years-should-we-give-sds-effect-size
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even">I just got back from the annual meetings of the American Economic Association (AEAs) in Boston. It’s been a couple of years since I last went, and after usually going to just development conferences, it was interesting to see some of the work going on in other fields. Here are a few notes:<br />
<ul><li></li></ul></div></div></div>Mon, 05 Jan 2015 14:24:00 +0000David McKenzie1208 at http://blogs.worldbank.org/impactevaluationsDoes the intra-class correlation matter for power calculations if I am going to cluster my standard errors anyway?
http://blogs.worldbank.org/impactevaluations/does-the-intra-class-correlation-matter-for-power-calculations-if-i-am-going-to-cluster-my-standard
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>This was a question posed by one of our readers in a <a href="http://blogs.worldbank.org/impactevaluations/tools-of-the-trade-intra-cluster-correlations#comment-9997"><font color="#0000ff">comment</font></a> on an earlier post I did on how to calculate the intra-class correlation in Stata.</p></div></div></div>Tue, 22 Jan 2013 00:18:42 +0000David McKenzie937 at http://blogs.worldbank.org/impactevaluationsPower Calculations for Propensity Score Matching?
http://blogs.worldbank.org/impactevaluations/power-calculations-for-propensity-score-matching
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span style="FONT-SIZE: 10pt">I received a question this week from </span><a href="http://go.worldbank.org/HCN92KM2G0"><span style="FONT-SIZE: 10pt"><font color="#0000ff">Kristen Himelein</font></span></a><span style="FONT-SIZE: 10pt">, a bank colleague who is working on an impact evaluation that will use propensity score matching.</span></p></div></div></div>Mon, 21 Nov 2011 01:52:08 +0000David McKenzie693 at http://blogs.worldbank.org/impactevaluationsgender power doesn't come cheap
http://blogs.worldbank.org/impactevaluations/gender-power-doesnt-come-cheap
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>coauthored with <span style="COLOR: #993300"><em>Alaka Holla</em></span></p>
<p>As we argued last week, we need more results that tell us what works and what does not for economically empowering women. And a first step would be for people who are running evaluations out there to run a regression that interacts gender with treatment. Now some of these will show no significant differences by sex. Does that mean that the program did not affect men and women differently? No. Alas, all zeroes are not created equal. </p></div></div></div>Tue, 26 Jul 2011 12:07:12 +0000Markus Goldstein612 at http://blogs.worldbank.org/impactevaluationsPower Calculations 101: Dealing with Incomplete Take-up
http://blogs.worldbank.org/impactevaluations/power-calculations-101-dealing-with-incomplete-take-up
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>A key issue in any impact evaluation is take-up (i.e. the proportion of people offered a program who use it). This is particularly an issue in many finance and private sector (FPD) programs. In many health and education programs such as vaccination campaigns or getting children to school programs, the goal of the program is actually to have all eligible individuals participate. In contrast, universal take-up is not the goal of most FPD programs, and, even when it is a goal, it is seldom the reality.</p></div></div></div>Mon, 23 May 2011 12:58:33 +0000David McKenzie568 at http://blogs.worldbank.org/impactevaluationsWhat is success, anyhow?
http://blogs.worldbank.org/impactevaluations/what-is-sucess-anyhow
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>As a fair number of impact evaluations I work on are programs designed by governments or NGOs, I often initially have to have a tricky discussion when it comes time to do the power calculations to design the impact evaluation. The subject of this conversation is the anticipated effect size. This is a key parameter – if it’s too optimistic you run the risk of an impact evaluation with no effect even when the program had worked to some (lesser) degree, if it’s too pessimistic, then you are wasting money and people’s time in your survey. </p></div></div></div>Tue, 19 Apr 2011 12:02:47 +0000Markus Goldstein544 at http://blogs.worldbank.org/impactevaluations