# One union win can open the next

> In NLRB data from 1961–2025, a close win is followed by 0.284–0.689 additional wins in the same state–industry cell over the next three years. In a separate experiment, information about wins moved support and beliefs about coworkers, but not significantly the interest in contacting an organizer.

## The short answer

A win can travel through results and through people’s expectations. The study’s boundary appears at the last step: a change in opinion is not proof of costly local action.

## The historical step

The authors compare NLRB elections clustered around the 50% threshold. A close win is followed by **0.284–0.689 additional wins** in the same state–industry cell over the next three years.

This is a range across specifications, not a confidence interval. The estimate is local to close elections and to the state–industry combinations in the analysis; it is not a universal multiplier.

## The experimental step

The experiment includes **9,089 hourly workers** in US retail and service jobs: 6,000 recruited through YouGov and 3,089 through Prolific. Participants received information about union wins, job-finding ease, both, or neither.

In the main table, union-win information is associated with:

- `+0.091 SD` for the union-support index (`N=7,588`);
- `+0.076 SD` for perceived coworker support (`N=7,635`);
- `+0.3 percentage points` for interest in contacting an organizer, not statistically significant (`N=7,581`).

The control mean for contact interest is `23.9%`. “Not significant” does not mean “zero effect”; it means this estimate does not provide sufficient statistical evidence for an increase.

## What it does not say

- The historical data are from the US and cover NLRB elections from 1961–2025.
- The experiment uses online-recruited hourly workers in retail and service jobs; it is not an estimate for all workers or for Romania.
- Support and stated intentions are not union formation, and contact interest is not observed action.
- The source is an August 2026 NBER working paper, not a peer-reviewed article; the version and tables may change.

## Source

[Winning is Contagious: Social Learning and the Dynamics of Union Support](https://www.nber.org/papers/w35571), Ellora Derenoncourt, Arindrajit Dube, Suresh Naidu, Heather Sarsons and Niharika Singh, NBER Working Paper 35571, DOI `10.3386/w35571`, August 2026. The experiment is registered as `AEARCTR0014948`.

This project synthesizes reported results and does not republish individual data, identities, or source figures.