quant research // summarizing the paperLOADING
Luis Enrique Correa Rocha · 2026-07-07
The authors built a daily index of U.S. economic news sentiment from 24 newspapers over 1980-2025 and studied how its dynamics changed. The average balance of positive versus negative coverage stayed broadly stable, but sentiment became much more persistent: optimistic or pessimistic moods now last longer, reverse less often, and separate into more distinct states, with negative bursts lasting longer than positive ones.
Why it matters: If news sentiment increasingly moves in long-lived regimes rather than resetting daily, practitioners using media-sentiment signals may want to model them as persistent episodes with memory rather than short-lived shocks. This could matter for how sentiment indicators are smoothed, timed, or combined with other data, though the paper studies news text itself, not returns or trading outcomes.
⚠ This is a descriptive study of news-text sentiment dynamics only — it makes no link to asset returns, trading performance, or profitability.
Collective emotion is often inferred from the tone of mass media, but such emotion is not directly observed. One approximation is to extract sentiment from text and use sentiment indexes as proxies to study the temporal organization of news sentiment. Using a daily index of U.S. economic news sentiment from 24 newspapers (1980-2025), we examine whether the response time of this sentiment process has changed. Although the average balance of positive and negative coverage has remained broadly stable, the persistence of news sentiment states has increased substantially. In dynamical terms, this implies longer residence times in optimistic or pessimistic regimes and weaker short-run correction of sentiment shocks. Complementary statistics show declining sentiment volatility, fewer reversals, and increasing bimodality, i.e. a stronger separation between positive and negative sentiment states. We also find an asymmetry between bursts of negative and positive sentiment, with negative bursts tending to last longer. These patterns are consistent with a minimal endogenous-memory model in which a slowly evolving latent sentiment component becomes more persistent while short-range corrective feedback weakens. The findings indicate a change in the temporal response of the U.S. economic newspaper sentiment index over the last 45 years, with sentiment shocks leaving longer traces than expected under short-memory exponential decay. News-based sentiment is thus better modeled as persistent episodes rather than as daily reactions that reset after each event.
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AI summary generated from the paper’s public abstract via arXiv; it may miss nuance — read the source before relying on it. Thank you to arXiv for its open-access interoperability; StockTools is not affiliated with arXiv, and all rights remain with the authors. Educational only, not financial advice.