Pure Signaling Value of Grade Discontinuities
RCTReview
Assessing whether wage increases stem from human capital or pure informational signaling requires isolating credential threshold shifts from continuous underlying ability.
Picture this
Reporting performance in broad discrete grade bands creates an artificial cutoff where individuals just above and below the line have virtually identical underlying test scores but receive different official letters. Comparing earnings across this boundary acts like testing if a gold seal on a diploma increases salary independently of actual test performance.
What the evidence says
Crossing a certificate score band cutoff raised 4-year earnings by 0.332 standard deviations (p = 0.13 for optimal bandwidth, p < 0.10 for double bandwidth), confirming that official band labels directly drive wage premiums.
- Who was studied
- N = 246 job-seekers assigned to the job application workshop in Addis Ababa, Ethiopia.
- How
- Regression Discontinuity Design (RDD) exploiting normalized score cutoffs across Raven, mathematical, linguistic, and work-sample test bands.
What to do
Design multi-tiered categorical certification bands that clearly delineate candidate performance thresholds to maximize employer trust and signaling impact.
From the source
"We find that being placed in a higher band generates a large, but noisily estimated increase in wages in 2018... being just above the cut-off leads to large increase in earnings of 0.33 standard deviations..."
Anonymity_or_Distance_Job_Search_and_Labour_Market_Exclusion_in.pdf