![]() |
| Source: https://chatmaxima.com/ |
Cover letters used to provide insight to hiring managers and helped them identify which candidates to select for an interview. A well-written cover letter signaled something about the quality of a candidate. Moreover, a well-tailored letter also could signal that a candidate was serious about the particular job opening. Do cover letters still have signaling value in the age of AI?
Several months ago, Jingyi Cui, Gabriel Dias, and Justin Ye published a working paper titled "Signaling in the Age of AI: Evidence from Cover Letters." They studied over 5 million cover letters submitted to 100,000 jobs on freelancer.com platform. The examined the impact of a new feature on the platform that uses AI to generate cover letters for job candidates. Perhaps not surprisingly, "Access to the tool increased textual alignment between cover letters and job posts and raised callback rates."
However, that is not the end of the story. The key finding pertained to a substantial drop in the correlation between cover-letter tailoring and invitations to interview, as well as a significant drop in the correlation with job offers. On the other hand, workers' review scores (a metric developed by the platform to evaluate past work experiences) became more meaningful. The authors conclude "These patterns suggest that as AI adoption increases, employers substitute away from easily manipulated signals like cover letters toward harder-to-fake indicators of quality."
Finally, the scholars examined whether people spent time revising or editing the AI-generated cover letter. Many people did not. Yet, those people who did edit the letters increased their probability of landing the job!
Interestingly, another study by Galdin and Silbert also studied job candidates on the freelancer.com platform. They found that the length of applications increased after the introduction of AI tools to help candidates. At the same time, "employers had a high willingness to pay for workers with more customized applications in the period before LLMs were introduced, but not after." In short, they discovered a drop in the value of the well-crafted application as a signal of quality. That drop had important implications. They write, "Without costly signaling, employers are less able to identify high-ability workers, causing the market to become significantly less meritocratic: compared to the pre-LLM equilibrium, workers in the top quintile of the ability distribution are hired 19% less often, workers in the bottom quintile are hired 14% more often."

