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+% Owner: Stage E, Agent 10 (writing). Numbers: tables/macros.tex, sections/macros_stageE.tex. |
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\section{Related Literature and Hypotheses} |
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\label{sec:literature} |
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−Our study sits at the intersection of five strands of research: textual analysis in finance, the |
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−pricing of corporate disclosure, technology and innovation in asset pricing, investor attention and |
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−narrative economics, and the nascent literature on the economics of artificial intelligence. Each |
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−contributes a building block---a measurement tool, an object of study, a candidate risk factor, a |
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−behavioural mechanism, and a comparison case---and a sixth, methodological strand disciplines the |
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−inference. We take the strands in turn and close with the hypotheses they jointly motivate. |
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+The study draws on six strands of research: textual analysis in finance, the pricing of corporate |
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+disclosure, text-based measures of technology and AI exposure, investor attention, the AI-washing |
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+and cybersecurity-disclosure literatures that bear on what the measure captures, and the |
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+methodological literature on short samples, multiple testing and event-study inference. We take |
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+the strands in turn, place the paper against its three closest competitors, and close with the |
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+hypotheses. |
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\subsection{Textual analysis and natural language processing in finance} |
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+\label{subsec:lit_text} |
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A now-large literature extracts economic signals from financial text. \citet{tetlock2007} showed |
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that the tone of a \textit{Wall Street Journal} column forecasts aggregate returns, and |
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\citet{tetlock2008} extended this to firm-level news. \citet{lm2011} demonstrated that |
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finance-specific sentiment dictionaries materially outperform general-purpose word lists in 10-K |
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−analysis, launching a wave of dictionary-based studies; \citet{lm2016} and \citet{lm2020} survey |
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−the field and its pitfalls, including the sensitivity of results to document selection and |
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−pre-processing. A second generation moved from counting words to modelling them: \citet{gentzkow2019} |
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−review text-as-data methods in economics, \citet{kekellyxiu2019} develop a supervised topic model |
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−that predicts returns from news, \citet{kelly2019textregression} propose a sparse text-regression |
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−framework, and \citet{bybee2024narrative} recover a ``state of the economy'' from business news. |
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−A third generation uses distributed representations of meaning. \citet{hanleyhoberg2019} apply word |
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+analysis; \citet{lm2016} and \citet{lm2020} survey the field and its pitfalls, including the |
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+sensitivity of results to document selection and pre-processing. A second generation moved from |
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+counting words to modelling them: \citet{gentzkow2019} review text-as-data methods in economics, |
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+\citet{kekellyxiu2019} develop a supervised topic model that predicts returns from news, |
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+\citet{kelly2019textregression} propose a sparse text-regression framework, and |
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+\citet{bybee2024narrative} recover a ``state of the economy'' from business news. A third |
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+generation uses distributed representations of meaning. \citet{hanleyhoberg2019} apply word |
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embeddings to bank 10-Ks to identify emerging risks before they are named in dictionaries; |
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\citet{limai2021} measure corporate culture from earnings calls with word embeddings; |
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\citet{huang2023finbert} show that a domain-adapted transformer outperforms dictionaries and |
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bag-of-words classifiers on financial text; and \citet{cong2022textfactor} build interpretable |
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−``textual factors'' from embeddings. Our paper belongs to this embedding-based generation. The |
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−limitations of keyword counting are acute for a theme like AI: a count cannot distinguish ``we do |
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−not currently use artificial intelligence'' from ``we are an artificial-intelligence leader,'' it |
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−misses the paraphrase of a firm that describes machine learning without writing ``AI,'' and it |
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−treats boilerplate and substance identically. We instead measure the semantic similarity of each |
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−passage to anchor concepts with a sentence transformer \citep{reimers2019sbert}, a design close in |
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−spirit to the similarity-to-reference-text constructions of \citet{hanleyhoberg2019}. The |
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−literature also warns, however, that text-based measures inherit the composition of the corpus they |
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−are computed on \citep{lm2016,lm2020}; Section~\ref{sec:data} therefore documents that composition |
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−in detail. |
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+``textual factors'' from embeddings. The firm-level exposure measures of \citet{hassan2019firmlevel} |
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+(political risk from earnings-call text), \citet{davis2020exposures} (COVID-19 exposures), |
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+\citet{bloom2021diffusion} (technology diffusion from patents, calls and job postings) and |
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+\citet{kim2023llmrisks} (risk assessments produced by a generative model) are the direct |
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+methodological lineage of a construct-specific score computed from a firm's own text. |
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+ |
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+Our paper belongs to the embedding-based generation. Its measure is the semantic similarity of |
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+each passage to anchor paragraphs, computed with a sentence transformer |
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+\citep{reimers2019sbert}---a design close in spirit to the similarity-to-reference-text |
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+constructions of \citet{hanleyhoberg2019} and \citet{celenymarechal2024cyber}. Embeddings have |
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+two advantages over a keyword count: a passage that describes machine learning without writing |
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+``AI'' is scored, and a count of the acronym does not distinguish a risk-factor boilerplate from |
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+an operating description. They also have limits that \cref{subsec:construct} measures rather |
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+than assumes. The first version of this paper claimed that the embedding separates ``we do not |
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+currently use artificial intelligence'' from ``we are an artificial-intelligence leader''; a |
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+direct probe shows that it does so only in part---negated sentences score lower than affirmative |
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+ones (\mProbeNegated{} against \mProbeAffirm{} on the adoption anchor) but still above the |
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+\mProbeNegatedPct{}th percentile of corpus chunks---so the claim is withdrawn. Sentence encoders |
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+of the MiniLM class are known to be weakly sensitive to negation, and the measure should be read |
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+as topical proximity to AI vocabulary rather than as a stance. The literature also warns that |
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+text-based measures inherit the composition of the corpus they are computed on |
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+\citep{lm2016,lm2020} and that firms adapt their language to the machines that read it |
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+\citep{cao2023machinelistening}; \cref{sec:data,subsec:construct} therefore document the corpus |
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+composition, the encoder's input window and the keyword baseline in detail. |
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\subsection{The pricing of corporate disclosure} |
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A parallel literature asks whether the \emph{content} and \emph{changes} of mandatory disclosure |
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reports relative to the prior year experience predictable future returns and operating outcomes. |
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\citet{hoberg2010product} and \citet{hobergphillips2016} use 10-K product descriptions to build |
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text-based industry classifications that carry asset-pricing content. \citet{lopezlira2023risk} |
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−extracts priced risk exposures from risk-factor sections. The general lesson is that the |
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−qualitative portions of filings contain value-relevant information that markets process |
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−incompletely and with delay. We contribute a concept-level measure---AI engagement---computed from the annual, quarterly |
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−and current reports of a broad universe of U.S.\ listed firms, and we characterize how its relation to |
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−returns varies over time and across firm size, dimensions the disclosure-pricing literature has largely left implicit. |
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+extracts priced risk exposures from risk-factor sections. The lesson is that the qualitative |
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+portions of filings contain value-relevant information that markets process incompletely and with |
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+delay. We contribute a concept-level measure---AI engagement---computed from the annual, |
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+quarterly and current reports of a broad universe of U.S.\ listed firms, and we characterize how |
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+its association with returns varies over time and across firm size, two dimensions the |
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+disclosure-pricing literature has largely left implicit. |
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+ |
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+\subsection{Text-based AI exposure and the cross-section of returns: the closest papers} |
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+\label{subsec:lit_ai} |
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+Asset pricing has long sought to connect technological change to risk and return |
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+\citep{hirshleifer2013innovative,kogan2017technological,koganpapanikolaou2014}, and a recent |
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+literature measures AI exposure directly. \citet{babina2024aiinvestment} measure firm-level AI |
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+investment from job postings and r\'esum\'es and document faster growth among AI-adopting firms; |
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+\citet{acemoglu2022aijobs}, \citet{webb2020} and \citet{hampole2025ai} measure the exposure of |
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+occupations, establishments and firms' workforces to AI; \citet{acemoglu2020wrong} study the |
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+labour-market effects of industrial robots. Three papers of 2026 are the closest to ours and were |
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+absent from the first version. \citet{eisfeldt2026generative} construct a firm-level measure of |
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+\emph{generative}-AI exposure from the task content of occupations, show that a long--short |
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+portfolio on that measure earned large returns in the two weeks after ChatGPT's release, and |
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+separate this workforce exposure from firms' \emph{product} exposure to AI. \citet{basu2026aiexposure} |
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+build text-based AI-exposure measures from the earnings-call transcripts of some 13,800 firms in |
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+44 countries over 2010--2025, find that a one-standard-deviation change in exposure is associated |
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+with higher annual returns concentrated after the ChatGPT launch, and report that a U.S.\ |
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+long--short portfolio of high-exposure firms earns no abnormal return before the launch, once its |
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+large-cap growth tilts are accounted for, and a large one afterward. \citet{borri2026aifactor} |
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+measure exposure from realized consumption of language-model tokens and find a positive premium |
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+in developed markets. Three further papers bear on specific constructs: \citet{song2026productexposure} |
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+builds a product-exposure measure from 10-K business descriptions, which is the object our |
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+disruption-risk anchor targets; \citet{wulam2026genai} show that short-window reactions to AI |
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+discussions on earnings calls depend on whether the discussion conveys new or concrete |
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+information, a result that parallels our language-versus-projects contrast; and |
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+\citet{jha2024chatgpt} and \citet{lopezliratang2026} use a language model itself as the reader of |
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+corporate or news text. \citet{yilmazkuday2026chatgpt} examines the aggregate return response to |
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+ChatGPT. |
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+ |
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+\Cref{tab:positioning} places the paper against the three closest papers. Our measure is built |
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+from the firm's own mandatory filings across all three forms, which none of them uses; our return |
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+profile covers fifteen look-ahead-free formation cohorts on a current-membership universe rather |
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+than an event window; and our second measure---a language-model count of disclosed AI |
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+projects---has no counterpart. Where \citet{basu2026aiexposure} find the association concentrated |
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+after the launch, we find a modest association throughout the sample in regression form and a |
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+post-launch increase confined to the largest firms; the two readings are not incompatible, because |
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+their sample is dominated by the large firms in which we also find the increase, but the |
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+difference in universe, text source and horizon should be kept in mind. Where |
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+\citet{eisfeldt2026generative} and \citet{song2026productexposure} distinguish labour from product |
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+exposure, our three anchors map imperfectly onto that distinction: the adoption anchor describes |
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+the firm's own use of AI (closest to an operating, partly labour-saving exposure), the |
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+infrastructure anchor describes compute and data-center investment (a supplier or user position |
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+in the AI build-out, which neither measure targets), and the disruption-risk anchor describes the |
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+threat of AI to the firm's products (the product exposure of Song). The sign and timing of our |
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+disruption-risk spread are compared with their results in \cref{sec:discussion}. |
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−\subsection{Technology, innovation, and the cross-section of returns} |
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−Asset pricing has long sought to connect technological change to risk and return. |
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−\citet{hirshleifer2013innovative} show that innovative efficiency predicts returns; |
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−\citet{kogan2017technological} build market-based measures of innovation from patents and link them |
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−to growth and reallocation; \citet{koganpapanikolaou2014} show that investment-specific technology |
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−shocks shape the cross-section. A more recent literature studies AI exposure directly. |
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−\citet{babina2024aiinvestment} measure firm-level AI investment from job postings and r\'esum\'es |
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−and document faster growth among AI-adopting firms; \citet{acemoglu2022aijobs} and \citet{webb2020} |
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−measure the exposure of occupations and establishments to AI; \citet{acemoglu2020wrong} study the |
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−labour-market effects of industrial robots. Closest to us, \citet{eisfeldt2023generative} construct |
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−a firm-level measure of \emph{generative}-AI exposure from the task content of occupations and show |
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−that a long--short portfolio on that measure earned large returns in the weeks after ChatGPT's |
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−release; \citet{jha2024chatgpt} use ChatGPT itself to extract expected investment and employment |
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−policies from earnings calls; and \citet{lopezliratang2026} show that a large language model can |
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−rank news headlines in a way that predicts next-day returns. Our contribution relative to this work |
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−is to measure AI exposure from the firm's own disclosure language, available for some 2,500 firms |
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−at annual frequency, and to characterize the full time profile of its pricing across fifteen |
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−cohorts rather than an event window. Where \citet{eisfeldt2023generative} document a sharp |
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−repricing in the weeks around the launch, we ask whether a persistent, text-based exposure measure |
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−carried a premium before the launch and whether the premium after it is distinguishable from a |
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−technology-sector effect. |
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+\begin{table}[htbp]\centering\footnotesize |
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+\caption{\textbf{Positioning relative to the closest papers.} Qualitative summary of each paper's |
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+question, measure, sample and headline finding, taken from the published abstracts; no number of |
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+this paper is compared here.}\label{tab:positioning} |
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+\begin{tabular}{@{}p{3.1cm}p{3.6cm}p{3.1cm}p{5.6cm}@{}} |
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+\toprule |
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+Paper & Exposure measure & Sample & Headline finding and relation to this paper \\ |
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+\midrule |
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+\citet{eisfeldt2026generative} & Occupational task content of the workforce (generative-AI exposure); product exposure separated & U.S.\ listed firms, event window around 30 Nov 2022 & Long--short on workforce exposure earns large returns in the two weeks after the launch; labour and product exposures distinct. We use filing language, fifteen annual cohorts and a size split; our disruption-risk anchor is a product-exposure construct. \\ |
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+\addlinespace |
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+\citet{basu2026aiexposure} & Hybrid NLP on earnings-call transcripts; topic-specific AI measures & $\approx$13,800 firms, 44 countries, 2010--2025 & Return association concentrated after ChatGPT; U.S.\ long--short has no pre-launch alpha once large-cap growth tilts are controlled. Same question and event; we use mandatory filings, a U.S.\ Russell~3000 universe and a language-versus-projects contrast, and find the post-launch increase only among the largest firms. \\ |
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+\addlinespace |
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+\citet{borri2026aifactor} & Realized consumption of language-model tokens & U.S.\ and international equities & Positive premium on usage-based exposure, significant in developed markets. A third exposure construct; usage rather than disclosure. \\ |
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+\addlinespace |
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+This paper & Sentence-embedding similarity of 10-K, 10-Q and 8-K text to anchor passages; LLM count of disclosed AI projects & \mnFirms{} firms (current S\&P~500 $\cup$ IWV holdings), formation cohorts 2010--2024 & Modest regression-robust, sort-fragile association over the full sample, conditional on survival; post-launch increase confined to the largest thousand firms and the 2024 cohort; no detectable premium on disclosed projects. \\ |
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+\bottomrule |
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+\end{tabular} |
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+\end{table} |
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−\subsection{Investor attention, salience, and narrative economics} |
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+\subsection{Investor attention, salience, and the size gradient} |
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Why might value-relevant disclosure be priced only after a catalyst? The behavioural literature |
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offers a mechanism: limited investor attention. \citet{barberodean2008} show that individual |
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investors are drawn to attention-grabbing stocks; \citet{da2011} construct an attention proxy from |
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released when attention is low; and \citet{hirshleifer2009driven} show that earnings news is |
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underweighted when investors are distracted. \citet{shiller2017narrative} argues that contagious |
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narratives drive major asset-price movements, and \citet{bakerwurgler2006} show that sentiment |
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−differentially affects hard-to-value, speculative stocks. These mechanisms predict that a salient |
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−consumer event such as ChatGPT could draw attention to information that had been sitting in filings |
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−for years. They do not, however, distinguish a firm-level attention shock from a sector-level |
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−revision of expected cash flows, and our tests are designed to separate the two. |
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+differentially affects hard-to-value, speculative stocks. \citet{honglimstein2000} show that |
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+firm-specific information diffuses more slowly among small, lightly covered firms, which is the |
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+natural prediction for where a disclosure-based signal should be priced with the longest delay. |
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+These mechanisms predict that a salient consumer event such as ChatGPT could draw attention to |
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+information that had been sitting in filings for years, and that the effect should be larger |
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+where attention frictions are larger. They do not distinguish a firm-level attention shock from a |
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+sector-level revision of expected cash flows, and our designs separate the two only partially: |
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+no attention proxy is in the panel, so the size gradient is the only attention-related test. |
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−\subsection{ESG and climate disclosure as a comparison case} |
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−Our placebo design connects to the literature on the pricing of ESG and climate disclosure. |
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−\citet{pastor2021sustainable} model how sustainability preferences depress the expected returns of |
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−green assets in equilibrium, and \citet{pastor2022dissecting} show that green stocks' strong |
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−realized returns through 2021 reflected unexpected increases in climate concern rather than high |
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−expected returns. \citet{bolton2021risk} document a carbon premium, and \citet{sautner2023} build a |
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−firm-level climate-exposure measure from earnings-call language that is priced in options and |
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−returns. Consistent with the post-2021 reversal in this literature, we find that high-ESG and |
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−high-climate disclosure earned negative spreads after 2022, which helps to rule out a generic |
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−``more disclosure earns more'' explanation of the AI result. |
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+\subsection{AI washing, cybersecurity disclosure, and what a language measure captures} |
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+\label{subsec:lit_washing} |
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+Two literatures bear on the interpretation of a premium on AI \emph{language} that is absent on |
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+AI \emph{projects}. The first names the phenomenon ``AI washing'': \citet{erdogan2026aiwashing} |
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+study the disclosure response of U.S.\ firms to the SEC's warnings about unsupported AI claims, |
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+and \citet{wang2026aiwashing} find that AI washing earns a short-lived post-disclosure |
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+abnormal-return premium that later reverses. Our reading of the language premium as a premium on |
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+``sounding like an AI firm'' is the AI-washing hypothesis, and it carries a testable |
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+implication---reversal at longer horizons---that \cref{subsec:spidres} examines. The second |
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+documents a cybersecurity premium: \citet{celenymarechal2024cyber} measure the proximity of 10-K |
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+text to a cyber corpus with a construction like ours and find that high-cyber-risk stocks earn |
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+higher returns, and \citet{kearney2025cyberchatgpt} study cyber risk around the ChatGPT launch. |
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+The cybersecurity spread that our placebo design produces is therefore a documented premium, not |
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+an unexplained artefact, and \cref{subsec:placebo,subsec:spidres} report the correlation of the |
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+two measures and a cyber-neutral AI sort. The ESG and climate placebos connect to |
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+\citet{pastor2021sustainable}, \citet{pastor2022dissecting}, \citet{bolton2021risk} and |
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+\citet{sautner2023}; consistent with the post-2021 reversal in that literature, high-ESG and |
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+high-climate language earned negative spreads after 2022. |
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−\subsection{Short samples, data snooping, and event-study inference} |
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−Two methodological literatures bear directly on how much weight our post-2022 estimates can carry. |
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−The first concerns the credibility of cross-sectional return patterns. \citet{harveyliuzhu2016} |
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−argue that the multiplicity of tested predictors requires $t$-statistics well above conventional |
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−thresholds; \citet{houxuezhang2020} find that most published anomalies fail to replicate under |
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−standard procedures; and \citet{mcleanpontiff2016} document post-publication decay. A spread |
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−estimated on three annual observations, one of which is extreme, must be read in that light. The |
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−second concerns inference in event studies when all firms share a single event date, so that |
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−abnormal returns are cross-sectionally correlated \citep{brownwarner1985,kolari2010} and |
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−event-induced variance may differ from estimation-window variance \citep{boehmer1991}, and in |
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−long-horizon settings, where the choice of benchmark and the compounding of abnormal returns |
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−matter \citep{barberlyon1997,fama1998,mitchellstafford2000,kothariwarner2007}. Our event-study |
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−inference follows the portfolio approach recommended in that literature. Finally, the use of a |
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−current-membership universe raises the survivorship concerns analysed by |
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−\citet{browngoetzmannross1995}, which we address with restrictions on listing history. |
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+\subsection{Short samples, multiple testing, survivorship, and event-study inference} |
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+Four methodological literatures govern how much weight the estimates can carry. |
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+\citet{harveyliuzhu2016} argue that the multiplicity of tested predictors requires $t$-statistics |
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+well above conventional thresholds; \citet{houxuezhang2020} find that most published anomalies |
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+fail to replicate under standard procedures; and \citet{mcleanpontiff2016} document |
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+post-publication decay. A spread estimated on three annual observations, one of which is extreme, |
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+must be read in that light, and \cref{subsec:mht} reports family sizes, adjusted $p$-values, a |
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+deflated Sharpe ratio and a specification curve. The use of a current-membership universe raises |
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+the survivorship and look-back selection analysed by \citet{browngoetzmannross1995}; the first |
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+version addressed it with restrictions on listing history, which condition on entry, not on exit, |
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+and \cref{subsec:survivorship} replaces them with point-in-time holdings, attrition rates and a |
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+bounding exercise. Event studies in which all firms share a single date have cross-sectionally |
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+correlated abnormal returns \citep{brownwarner1985,kolari2010}, event-induced variance |
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+\citep{boehmer1991} and, at long horizons, a dependence on the benchmark and the compounding |
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+convention \citep{barberlyon1997,fama1998,mitchellstafford2000,kothariwarner2007}; our inference |
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+follows the portfolio approach of that literature and reports every statistic under several |
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+benchmarks. Finally, inference in panels with few time clusters follows |
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+\citet{petersen2009}, \citet{thompson2011} and \citet{cameron2011}. |
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|
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\subsection{Hypotheses} |
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\label{subsec:hypotheses} |
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−Our analysis is organized around four hypotheses. |
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+The analysis is organized around five hypotheses, each stated as a prediction about an |
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+association and each with the clause that would falsify it. |
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\begin{description}[leftmargin=2.4em,style=nextline] |
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−\item[H1 (Unconditional pricing).] If AI exposure carries a stable risk premium or persistent |
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−mispricing, then sorting on AI-disclosure intensity yields a positive and significant risk-adjusted |
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−return spread over the full 2010--2024 formation sample. |
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+\item[H1 (Unconditional association).] If AI exposure carries a stable premium or persistent |
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+mispricing, sorting on AI-disclosure intensity yields a positive risk-adjusted return spread over |
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+the full 2010--2024 formation sample, in sort and in regression form, that survives winsorization. |
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\item[H2 (Regime dependence).] If instead AI exposure is repriced only once AI becomes salient, the |
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−return spread is small before and large after the late-2022 generative-AI catalyst, and the |
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−increase is visible in each post-launch cohort rather than in a single one. |
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+return spread is small before and large after the late-2022 generative-AI catalyst, the increase |
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+is visible in each post-launch cohort rather than in a single one, and the 2022 break date stands |
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+out among placebo break dates. |
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\item[H3 (AI-specificity).] If the post-2022 spread reflects an AI repricing rather than a |
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−mechanical or market-wide artefact, it appears for AI-related semantic factors but not for unrelated |
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−factors such as ESG, climate, or macro risk, and it is not spanned by a technology-sector factor. |
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+mechanical or market-wide artefact, (a) it appears for AI-related semantic factors but not for |
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+unrelated factors such as ESG, climate or macro risk, and (b) it is not spanned by a |
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+technology-sector factor. |
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\item[H4 (Cross-sectional, not within-firm).] If the market repriced \emph{which} firms are |
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−AI-exposed rather than rewarding incremental wording, the effect is concentrated in the |
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−cross-section, attenuates under firm fixed effects, and displays no pre-trend when exposure is held |
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−fixed at its pre-launch level. |
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−\end{description} |
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−\noindent We add a fifth hypothesis that the broad universe makes testable. |
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−\begin{description}[leftmargin=2.4em,style=nextline] |
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−\item[H5 (Size and attention).] If the post-launch repricing reflects limited attention rather than a |
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−revision of sector cash flows, it is stronger among smaller, less-followed firms than among the largest |
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−thousand, and it is visible in the firm's own disclosed AI projects as well as in its language. |
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+AI-exposed rather than rewarding incremental wording, the association is concentrated in the |
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+cross-section, attenuates under firm fixed effects, and the event-time profile of a pre-determined |
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+exposure shows no differential trend before the launch and a positive shift after it. |
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+\item[H5 (Size and projects).] (a) If the post-launch repricing reflects limited attention rather |
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+than a revision of sector cash flows, it is stronger among smaller, less-followed firms than among |
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+the largest thousand. (b) If the language premium reflects concrete AI activity, it is visible in |
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+the firm's own disclosed AI projects as well as in its language. |
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\end{description} |
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−\noindent Section~\ref{sec:discussion} summarizes what the Russell~3000 evidence says about each hypothesis. |
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+\noindent \Cref{subsec:verdicts} records, clause by clause, what the Russell~3000 evidence says |
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+about each hypothesis. |
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|