Individual Fixed Effects Precision Enhancement in Panel RCTs

In Simple Words

Adding individual fixed effects into statistical models subtracts away each participant's unique, permanent personal habits, allowing researchers to evaluate the pure impact of the experimental tool like comparing a runner's time against their own personal average rather than against the entire crowd.

Research question

High baseline variance in weekly individual financial behavior introduces residual noise that reduces statistical power in randomized evaluations of financial tools.

Participants

N = 4,451 Filipino migrant workers in the UAE evaluated over 137,927 weekly observations across 30 weeks.

Study Design

Intent-to-treat (ITT) Ordinary Least Squares (OLS) panel regression incorporating individual participant fixed effects and week fixed effects to control for time-invariant individual variation and temporal shocks.

Results

Including individual fixed effects controlled for baseline individual variation, achieving an adjusted R-squared of 0.010 for weekly remittance probability and 0.012 for the low-baseline remittance subsample, ensuring identification precision across 137,927 panel observations.

Takeaway

Incorporate individual participant fixed effects in panel RCT regressions to absorb time-invariant individual heterogeneity and boost statistical precision.

Read alongside the research

Plain-English glossary

Original explanations, informed by the references below. Examples are illustrations, not data from the studies above. The research text stays unchanged.

Baseline

The starting measurements in a study. Researchers use these to compare what participants were like at the start with what happens later.

ExampleBefore a training programme starts, researchers measure workers’ earnings. That first measurement is the baseline.

GET-IT glossary · Baseline characteristics ↗Read more about baseline →

Randomized controlled trial

A study that uses chance, like drawing lots, to decide who receives each option being compared. Researchers compare the groups’ outcomes to estimate the effect of those options.

ExampleA lottery assigns volunteers to a training programme or a comparison group. Researchers then compare their outcomes.

GET-IT glossary · Randomized study ↗Read more about randomized controlled trial →

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