In Simple Words
Think of job hunting like sending college applications. The first friction happens when many students apply to the exact same university, leaving smaller colleges with zero applicants. The second friction happens when a university offers admission to top applicants, but those applicants choose other universities instead, leaving the original university with unfilled seats and no time to process waitlisted students.
Research question
Standard aggregate Cobb-Douglas matching functions assume constant returns and smooth matching efficiency, ignoring how increasing individual application volume creates discrete coordination bottlenecks on both the applicant and employer sides.
Participants
Theoretical matching framework calibrated using Indirect Inference on N = 40,403 Danish job seekers across 14 county labor markets.
Study Design
Micro-founded directed search matching function $m(a; \bar{a}, \theta) = 1 - (1 - \psi)^a$ with Poisson-distributed vacancy applications ($\psi = \frac{\theta}{\bar{a}}(1 - e^{-\bar{a}/\theta})$).
Results
While higher search effort per worker resolves the first friction (reducing empty vacancies), it exacerbates the second friction (increasing double-job offers and candidate loss), causing aggregate matching efficiency to flatten and diminish beyond optimal application thresholds.
Takeaway
Specify matching functions with explicit dual-coordination friction parameters to model non-linear matching returns under policy-induced search effort spikes.