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2 | +% Owner: Stage E, Agent 10 (writing). Numbers: tables/macros.tex, sections/macros_stageE.tex. |
| 2 | \section{Related Literature and Hypotheses} |
3 | \section{Related Literature and Hypotheses} |
| 3 | \label{sec:literature} |
4 | \label{sec:literature} |
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5 | % ============================================================================ |
| 5 | |
6 | |
| 6 | −Our study sits at the intersection of five strands of research: textual analysis in finance, the |
7 | +The study draws on six strands of research: textual analysis in finance, the pricing of corporate |
| 7 | −pricing of corporate disclosure, technology and innovation in asset pricing, investor attention and |
8 | +disclosure, text-based measures of technology and AI exposure, investor attention, the AI-washing |
| 8 | −narrative economics, and the nascent literature on the economics of artificial intelligence. Each |
9 | +and cybersecurity-disclosure literatures that bear on what the measure captures, and the |
| 9 | −contributes a building block---a measurement tool, an object of study, a candidate risk factor, a |
10 | +methodological literature on short samples, multiple testing and event-study inference. We take |
| 10 | −behavioural mechanism, and a comparison case---and a sixth, methodological strand disciplines the |
11 | +the strands in turn, place the paper against its three closest competitors, and close with the |
| 11 | −inference. We take the strands in turn and close with the hypotheses they jointly motivate. |
12 | +hypotheses. |
| 12 | |
13 | |
| 13 | \subsection{Textual analysis and natural language processing in finance} |
14 | \subsection{Textual analysis and natural language processing in finance} |
| |
15 | +\label{subsec:lit_text} |
| 14 | A now-large literature extracts economic signals from financial text. \citet{tetlock2007} showed |
16 | A now-large literature extracts economic signals from financial text. \citet{tetlock2007} showed |
| 15 | that the tone of a \textit{Wall Street Journal} column forecasts aggregate returns, and |
17 | that the tone of a \textit{Wall Street Journal} column forecasts aggregate returns, and |
| 16 | \citet{tetlock2008} extended this to firm-level news. \citet{lm2011} demonstrated that |
18 | \citet{tetlock2008} extended this to firm-level news. \citet{lm2011} demonstrated that |
| 17 | finance-specific sentiment dictionaries materially outperform general-purpose word lists in 10-K |
19 | finance-specific sentiment dictionaries materially outperform general-purpose word lists in 10-K |
| 18 | −analysis, launching a wave of dictionary-based studies; \citet{lm2016} and \citet{lm2020} survey |
20 | +analysis; \citet{lm2016} and \citet{lm2020} survey the field and its pitfalls, including the |
| 19 | −the field and its pitfalls, including the sensitivity of results to document selection and |
21 | +sensitivity of results to document selection and pre-processing. A second generation moved from |
| 20 | −pre-processing. A second generation moved from counting words to modelling them: \citet{gentzkow2019} |
22 | +counting words to modelling them: \citet{gentzkow2019} review text-as-data methods in economics, |
| 21 | −review text-as-data methods in economics, \citet{kekellyxiu2019} develop a supervised topic model |
23 | +\citet{kekellyxiu2019} develop a supervised topic model that predicts returns from news, |
| 22 | −that predicts returns from news, \citet{kelly2019textregression} propose a sparse text-regression |
24 | +\citet{kelly2019textregression} propose a sparse text-regression framework, and |
| 23 | −framework, and \citet{bybee2024narrative} recover a ``state of the economy'' from business news. |
25 | +\citet{bybee2024narrative} recover a ``state of the economy'' from business news. A third |
| 24 | −A third generation uses distributed representations of meaning. \citet{hanleyhoberg2019} apply word |
26 | +generation uses distributed representations of meaning. \citet{hanleyhoberg2019} apply word |
| 25 | embeddings to bank 10-Ks to identify emerging risks before they are named in dictionaries; |
27 | embeddings to bank 10-Ks to identify emerging risks before they are named in dictionaries; |
| 26 | \citet{limai2021} measure corporate culture from earnings calls with word embeddings; |
28 | \citet{limai2021} measure corporate culture from earnings calls with word embeddings; |
| 27 | \citet{huang2023finbert} show that a domain-adapted transformer outperforms dictionaries and |
29 | \citet{huang2023finbert} show that a domain-adapted transformer outperforms dictionaries and |
| 28 | bag-of-words classifiers on financial text; and \citet{cong2022textfactor} build interpretable |
30 | bag-of-words classifiers on financial text; and \citet{cong2022textfactor} build interpretable |
| 29 | −``textual factors'' from embeddings. Our paper belongs to this embedding-based generation. The |
31 | +``textual factors'' from embeddings. The firm-level exposure measures of \citet{hassan2019firmlevel} |
| 30 | −limitations of keyword counting are acute for a theme like AI: a count cannot distinguish ``we do |
32 | +(political risk from earnings-call text), \citet{davis2020exposures} (COVID-19 exposures), |
| 31 | −not currently use artificial intelligence'' from ``we are an artificial-intelligence leader,'' it |
33 | +\citet{bloom2021diffusion} (technology diffusion from patents, calls and job postings) and |
| 32 | −misses the paraphrase of a firm that describes machine learning without writing ``AI,'' and it |
34 | +\citet{kim2023llmrisks} (risk assessments produced by a generative model) are the direct |
| 33 | −treats boilerplate and substance identically. We instead measure the semantic similarity of each |
35 | +methodological lineage of a construct-specific score computed from a firm's own text. |
| 34 | −passage to anchor concepts with a sentence transformer \citep{reimers2019sbert}, a design close in |
36 | + |
| 35 | −spirit to the similarity-to-reference-text constructions of \citet{hanleyhoberg2019}. The |
37 | +Our paper belongs to the embedding-based generation. Its measure is the semantic similarity of |
| 36 | −literature also warns, however, that text-based measures inherit the composition of the corpus they |
38 | +each passage to anchor paragraphs, computed with a sentence transformer |
| 37 | −are computed on \citep{lm2016,lm2020}; Section~\ref{sec:data} therefore documents that composition |
39 | +\citep{reimers2019sbert}---a design close in spirit to the similarity-to-reference-text |
| 38 | −in detail. |
40 | +constructions of \citet{hanleyhoberg2019} and \citet{celenymarechal2024cyber}. Embeddings have |
| |
41 | +two advantages over a keyword count: a passage that describes machine learning without writing |
| |
42 | +``AI'' is scored, and a count of the acronym does not distinguish a risk-factor boilerplate from |
| |
43 | +an operating description. They also have limits that \cref{subsec:construct} measures rather |
| |
44 | +than assumes. The first version of this paper claimed that the embedding separates ``we do not |
| |
45 | +currently use artificial intelligence'' from ``we are an artificial-intelligence leader''; a |
| |
46 | +direct probe shows that it does so only in part---negated sentences score lower than affirmative |
| |
47 | +ones (\mProbeNegated{} against \mProbeAffirm{} on the adoption anchor) but still above the |
| |
48 | +\mProbeNegatedPct{}th percentile of corpus chunks---so the claim is withdrawn. Sentence encoders |
| |
49 | +of the MiniLM class are known to be weakly sensitive to negation, and the measure should be read |
| |
50 | +as topical proximity to AI vocabulary rather than as a stance. The literature also warns that |
| |
51 | +text-based measures inherit the composition of the corpus they are computed on |
| |
52 | +\citep{lm2016,lm2020} and that firms adapt their language to the machines that read it |
| |
53 | +\citep{cao2023machinelistening}; \cref{sec:data,subsec:construct} therefore document the corpus |
| |
54 | +composition, the encoder's input window and the keyword baseline in detail. |
| 39 | |
55 | |
| 40 | \subsection{The pricing of corporate disclosure} |
56 | \subsection{The pricing of corporate disclosure} |
| 41 | A parallel literature asks whether the \emph{content} and \emph{changes} of mandatory disclosure |
57 | A parallel literature asks whether the \emph{content} and \emph{changes} of mandatory disclosure |
| 43 | reports relative to the prior year experience predictable future returns and operating outcomes. |
59 | reports relative to the prior year experience predictable future returns and operating outcomes. |
| 44 | \citet{hoberg2010product} and \citet{hobergphillips2016} use 10-K product descriptions to build |
60 | \citet{hoberg2010product} and \citet{hobergphillips2016} use 10-K product descriptions to build |
| 45 | text-based industry classifications that carry asset-pricing content. \citet{lopezlira2023risk} |
61 | text-based industry classifications that carry asset-pricing content. \citet{lopezlira2023risk} |
| 46 | −extracts priced risk exposures from risk-factor sections. The general lesson is that the |
62 | +extracts priced risk exposures from risk-factor sections. The lesson is that the qualitative |
| 47 | −qualitative portions of filings contain value-relevant information that markets process |
63 | +portions of filings contain value-relevant information that markets process incompletely and with |
| 48 | −incompletely and with delay. We contribute a concept-level measure---AI engagement---computed from the annual, quarterly |
64 | +delay. We contribute a concept-level measure---AI engagement---computed from the annual, |
| 49 | −and current reports of a broad universe of U.S.\ listed firms, and we characterize how its relation to |
65 | +quarterly and current reports of a broad universe of U.S.\ listed firms, and we characterize how |
| 50 | −returns varies over time and across firm size, dimensions the disclosure-pricing literature has largely left implicit. |
66 | +its association with returns varies over time and across firm size, two dimensions the |
| |
67 | +disclosure-pricing literature has largely left implicit. |
| |
68 | + |
| |
69 | +\subsection{Text-based AI exposure and the cross-section of returns: the closest papers} |
| |
70 | +\label{subsec:lit_ai} |
| |
71 | +Asset pricing has long sought to connect technological change to risk and return |
| |
72 | +\citep{hirshleifer2013innovative,kogan2017technological,koganpapanikolaou2014}, and a recent |
| |
73 | +literature measures AI exposure directly. \citet{babina2024aiinvestment} measure firm-level AI |
| |
74 | +investment from job postings and r\'esum\'es and document faster growth among AI-adopting firms; |
| |
75 | +\citet{acemoglu2022aijobs}, \citet{webb2020} and \citet{hampole2025ai} measure the exposure of |
| |
76 | +occupations, establishments and firms' workforces to AI; \citet{acemoglu2020wrong} study the |
| |
77 | +labour-market effects of industrial robots. Three papers of 2026 are the closest to ours and were |
| |
78 | +absent from the first version. \citet{eisfeldt2026generative} construct a firm-level measure of |
| |
79 | +\emph{generative}-AI exposure from the task content of occupations, show that a long--short |
| |
80 | +portfolio on that measure earned large returns in the two weeks after ChatGPT's release, and |
| |
81 | +separate this workforce exposure from firms' \emph{product} exposure to AI. \citet{basu2026aiexposure} |
| |
82 | +build text-based AI-exposure measures from the earnings-call transcripts of some 13,800 firms in |
| |
83 | +44 countries over 2010--2025, find that a one-standard-deviation change in exposure is associated |
| |
84 | +with higher annual returns concentrated after the ChatGPT launch, and report that a U.S.\ |
| |
85 | +long--short portfolio of high-exposure firms earns no abnormal return before the launch, once its |
| |
86 | +large-cap growth tilts are accounted for, and a large one afterward. \citet{borri2026aifactor} |
| |
87 | +measure exposure from realized consumption of language-model tokens and find a positive premium |
| |
88 | +in developed markets. Three further papers bear on specific constructs: \citet{song2026productexposure} |
| |
89 | +builds a product-exposure measure from 10-K business descriptions, which is the object our |
| |
90 | +disruption-risk anchor targets; \citet{wulam2026genai} show that short-window reactions to AI |
| |
91 | +discussions on earnings calls depend on whether the discussion conveys new or concrete |
| |
92 | +information, a result that parallels our language-versus-projects contrast; and |
| |
93 | +\citet{jha2024chatgpt} and \citet{lopezliratang2026} use a language model itself as the reader of |
| |
94 | +corporate or news text. \citet{yilmazkuday2026chatgpt} examines the aggregate return response to |
| |
95 | +ChatGPT. |
| |
96 | + |
| |
97 | +\Cref{tab:positioning} places the paper against the three closest papers. Our measure is built |
| |
98 | +from the firm's own mandatory filings across all three forms, which none of them uses; our return |
| |
99 | +profile covers fifteen look-ahead-free formation cohorts on a current-membership universe rather |
| |
100 | +than an event window; and our second measure---a language-model count of disclosed AI |
| |
101 | +projects---has no counterpart. Where \citet{basu2026aiexposure} find the association concentrated |
| |
102 | +after the launch, we find a modest association throughout the sample in regression form and a |
| |
103 | +post-launch increase confined to the largest firms; the two readings are not incompatible, because |
| |
104 | +their sample is dominated by the large firms in which we also find the increase, but the |
| |
105 | +difference in universe, text source and horizon should be kept in mind. Where |
| |
106 | +\citet{eisfeldt2026generative} and \citet{song2026productexposure} distinguish labour from product |
| |
107 | +exposure, our three anchors map imperfectly onto that distinction: the adoption anchor describes |
| |
108 | +the firm's own use of AI (closest to an operating, partly labour-saving exposure), the |
| |
109 | +infrastructure anchor describes compute and data-center investment (a supplier or user position |
| |
110 | +in the AI build-out, which neither measure targets), and the disruption-risk anchor describes the |
| |
111 | +threat of AI to the firm's products (the product exposure of Song). The sign and timing of our |
| |
112 | +disruption-risk spread are compared with their results in \cref{sec:discussion}. |
| 51 | |
113 | |
| 52 | −\subsection{Technology, innovation, and the cross-section of returns} |
114 | +\begin{table}[htbp]\centering\footnotesize |
| 53 | −Asset pricing has long sought to connect technological change to risk and return. |
115 | +\caption{\textbf{Positioning relative to the closest papers.} Qualitative summary of each paper's |
| 54 | −\citet{hirshleifer2013innovative} show that innovative efficiency predicts returns; |
116 | +question, measure, sample and headline finding, taken from the published abstracts; no number of |
| 55 | −\citet{kogan2017technological} build market-based measures of innovation from patents and link them |
117 | +this paper is compared here.}\label{tab:positioning} |
| 56 | −to growth and reallocation; \citet{koganpapanikolaou2014} show that investment-specific technology |
118 | +\begin{tabular}{@{}p{3.1cm}p{3.6cm}p{3.1cm}p{5.6cm}@{}} |
| 57 | −shocks shape the cross-section. A more recent literature studies AI exposure directly. |
119 | +\toprule |
| 58 | −\citet{babina2024aiinvestment} measure firm-level AI investment from job postings and r\'esum\'es |
120 | +Paper & Exposure measure & Sample & Headline finding and relation to this paper \\ |
| 59 | −and document faster growth among AI-adopting firms; \citet{acemoglu2022aijobs} and \citet{webb2020} |
121 | +\midrule |
| 60 | −measure the exposure of occupations and establishments to AI; \citet{acemoglu2020wrong} study the |
122 | +\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. \\ |
| 61 | −labour-market effects of industrial robots. Closest to us, \citet{eisfeldt2023generative} construct |
123 | +\addlinespace |
| 62 | −a firm-level measure of \emph{generative}-AI exposure from the task content of occupations and show |
124 | +\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. \\ |
| 63 | −that a long--short portfolio on that measure earned large returns in the weeks after ChatGPT's |
125 | +\addlinespace |
| 64 | −release; \citet{jha2024chatgpt} use ChatGPT itself to extract expected investment and employment |
126 | +\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. \\ |
| 65 | −policies from earnings calls; and \citet{lopezliratang2026} show that a large language model can |
127 | +\addlinespace |
| 66 | −rank news headlines in a way that predicts next-day returns. Our contribution relative to this work |
128 | +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. \\ |
| 67 | −is to measure AI exposure from the firm's own disclosure language, available for some 2,500 firms |
129 | +\bottomrule |
| 68 | −at annual frequency, and to characterize the full time profile of its pricing across fifteen |
130 | +\end{tabular} |
| 69 | −cohorts rather than an event window. Where \citet{eisfeldt2023generative} document a sharp |
131 | +\end{table} |
| 70 | −repricing in the weeks around the launch, we ask whether a persistent, text-based exposure measure |
| |
| 71 | −carried a premium before the launch and whether the premium after it is distinguishable from a |
| |
| 72 | −technology-sector effect. |
| |
| 73 | |
132 | |
| 74 | −\subsection{Investor attention, salience, and narrative economics} |
133 | +\subsection{Investor attention, salience, and the size gradient} |
| 75 | Why might value-relevant disclosure be priced only after a catalyst? The behavioural literature |
134 | Why might value-relevant disclosure be priced only after a catalyst? The behavioural literature |
| 76 | offers a mechanism: limited investor attention. \citet{barberodean2008} show that individual |
135 | offers a mechanism: limited investor attention. \citet{barberodean2008} show that individual |
| 77 | investors are drawn to attention-grabbing stocks; \citet{da2011} construct an attention proxy from |
136 | investors are drawn to attention-grabbing stocks; \citet{da2011} construct an attention proxy from |
| 79 | released when attention is low; and \citet{hirshleifer2009driven} show that earnings news is |
138 | released when attention is low; and \citet{hirshleifer2009driven} show that earnings news is |
| 80 | underweighted when investors are distracted. \citet{shiller2017narrative} argues that contagious |
139 | underweighted when investors are distracted. \citet{shiller2017narrative} argues that contagious |
| 81 | narratives drive major asset-price movements, and \citet{bakerwurgler2006} show that sentiment |
140 | narratives drive major asset-price movements, and \citet{bakerwurgler2006} show that sentiment |
| 82 | −differentially affects hard-to-value, speculative stocks. These mechanisms predict that a salient |
141 | +differentially affects hard-to-value, speculative stocks. \citet{honglimstein2000} show that |
| 83 | −consumer event such as ChatGPT could draw attention to information that had been sitting in filings |
142 | +firm-specific information diffuses more slowly among small, lightly covered firms, which is the |
| 84 | −for years. They do not, however, distinguish a firm-level attention shock from a sector-level |
143 | +natural prediction for where a disclosure-based signal should be priced with the longest delay. |
| 85 | −revision of expected cash flows, and our tests are designed to separate the two. |
144 | +These mechanisms predict that a salient consumer event such as ChatGPT could draw attention to |
| |
145 | +information that had been sitting in filings for years, and that the effect should be larger |
| |
146 | +where attention frictions are larger. They do not distinguish a firm-level attention shock from a |
| |
147 | +sector-level revision of expected cash flows, and our designs separate the two only partially: |
| |
148 | +no attention proxy is in the panel, so the size gradient is the only attention-related test. |
| 86 | |
149 | |
| 87 | −\subsection{ESG and climate disclosure as a comparison case} |
150 | +\subsection{AI washing, cybersecurity disclosure, and what a language measure captures} |
| 88 | −Our placebo design connects to the literature on the pricing of ESG and climate disclosure. |
151 | +\label{subsec:lit_washing} |
| 89 | −\citet{pastor2021sustainable} model how sustainability preferences depress the expected returns of |
152 | +Two literatures bear on the interpretation of a premium on AI \emph{language} that is absent on |
| 90 | −green assets in equilibrium, and \citet{pastor2022dissecting} show that green stocks' strong |
153 | +AI \emph{projects}. The first names the phenomenon ``AI washing'': \citet{erdogan2026aiwashing} |
| 91 | −realized returns through 2021 reflected unexpected increases in climate concern rather than high |
154 | +study the disclosure response of U.S.\ firms to the SEC's warnings about unsupported AI claims, |
| 92 | −expected returns. \citet{bolton2021risk} document a carbon premium, and \citet{sautner2023} build a |
155 | +and \citet{wang2026aiwashing} find that AI washing earns a short-lived post-disclosure |
| 93 | −firm-level climate-exposure measure from earnings-call language that is priced in options and |
156 | +abnormal-return premium that later reverses. Our reading of the language premium as a premium on |
| 94 | −returns. Consistent with the post-2021 reversal in this literature, we find that high-ESG and |
157 | +``sounding like an AI firm'' is the AI-washing hypothesis, and it carries a testable |
| 95 | −high-climate disclosure earned negative spreads after 2022, which helps to rule out a generic |
158 | +implication---reversal at longer horizons---that \cref{subsec:spidres} examines. The second |
| 96 | −``more disclosure earns more'' explanation of the AI result. |
159 | +documents a cybersecurity premium: \citet{celenymarechal2024cyber} measure the proximity of 10-K |
| |
160 | +text to a cyber corpus with a construction like ours and find that high-cyber-risk stocks earn |
| |
161 | +higher returns, and \citet{kearney2025cyberchatgpt} study cyber risk around the ChatGPT launch. |
| |
162 | +The cybersecurity spread that our placebo design produces is therefore a documented premium, not |
| |
163 | +an unexplained artefact, and \cref{subsec:placebo,subsec:spidres} report the correlation of the |
| |
164 | +two measures and a cyber-neutral AI sort. The ESG and climate placebos connect to |
| |
165 | +\citet{pastor2021sustainable}, \citet{pastor2022dissecting}, \citet{bolton2021risk} and |
| |
166 | +\citet{sautner2023}; consistent with the post-2021 reversal in that literature, high-ESG and |
| |
167 | +high-climate language earned negative spreads after 2022. |
| 97 | |
168 | |
| 98 | −\subsection{Short samples, data snooping, and event-study inference} |
169 | +\subsection{Short samples, multiple testing, survivorship, and event-study inference} |
| 99 | −Two methodological literatures bear directly on how much weight our post-2022 estimates can carry. |
170 | +Four methodological literatures govern how much weight the estimates can carry. |
| 100 | −The first concerns the credibility of cross-sectional return patterns. \citet{harveyliuzhu2016} |
171 | +\citet{harveyliuzhu2016} argue that the multiplicity of tested predictors requires $t$-statistics |
| 101 | −argue that the multiplicity of tested predictors requires $t$-statistics well above conventional |
172 | +well above conventional thresholds; \citet{houxuezhang2020} find that most published anomalies |
| 102 | −thresholds; \citet{houxuezhang2020} find that most published anomalies fail to replicate under |
173 | +fail to replicate under standard procedures; and \citet{mcleanpontiff2016} document |
| 103 | −standard procedures; and \citet{mcleanpontiff2016} document post-publication decay. A spread |
174 | +post-publication decay. A spread estimated on three annual observations, one of which is extreme, |
| 104 | −estimated on three annual observations, one of which is extreme, must be read in that light. The |
175 | +must be read in that light, and \cref{subsec:mht} reports family sizes, adjusted $p$-values, a |
| 105 | −second concerns inference in event studies when all firms share a single event date, so that |
176 | +deflated Sharpe ratio and a specification curve. The use of a current-membership universe raises |
| 106 | −abnormal returns are cross-sectionally correlated \citep{brownwarner1985,kolari2010} and |
177 | +the survivorship and look-back selection analysed by \citet{browngoetzmannross1995}; the first |
| 107 | −event-induced variance may differ from estimation-window variance \citep{boehmer1991}, and in |
178 | +version addressed it with restrictions on listing history, which condition on entry, not on exit, |
| 108 | −long-horizon settings, where the choice of benchmark and the compounding of abnormal returns |
179 | +and \cref{subsec:survivorship} replaces them with point-in-time holdings, attrition rates and a |
| 109 | −matter \citep{barberlyon1997,fama1998,mitchellstafford2000,kothariwarner2007}. Our event-study |
180 | +bounding exercise. Event studies in which all firms share a single date have cross-sectionally |
| 110 | −inference follows the portfolio approach recommended in that literature. Finally, the use of a |
181 | +correlated abnormal returns \citep{brownwarner1985,kolari2010}, event-induced variance |
| 111 | −current-membership universe raises the survivorship concerns analysed by |
182 | +\citep{boehmer1991} and, at long horizons, a dependence on the benchmark and the compounding |
| 112 | −\citet{browngoetzmannross1995}, which we address with restrictions on listing history. |
183 | +convention \citep{barberlyon1997,fama1998,mitchellstafford2000,kothariwarner2007}; our inference |
| |
184 | +follows the portfolio approach of that literature and reports every statistic under several |
| |
185 | +benchmarks. Finally, inference in panels with few time clusters follows |
| |
186 | +\citet{petersen2009}, \citet{thompson2011} and \citet{cameron2011}. |
| 113 | |
187 | |
| 114 | \subsection{Hypotheses} |
188 | \subsection{Hypotheses} |
| 115 | \label{subsec:hypotheses} |
189 | \label{subsec:hypotheses} |
| 116 | −Our analysis is organized around four hypotheses. |
190 | +The analysis is organized around five hypotheses, each stated as a prediction about an |
| |
191 | +association and each with the clause that would falsify it. |
| 117 | \begin{description}[leftmargin=2.4em,style=nextline] |
192 | \begin{description}[leftmargin=2.4em,style=nextline] |
| 118 | −\item[H1 (Unconditional pricing).] If AI exposure carries a stable risk premium or persistent |
193 | +\item[H1 (Unconditional association).] If AI exposure carries a stable premium or persistent |
| 119 | −mispricing, then sorting on AI-disclosure intensity yields a positive and significant risk-adjusted |
194 | +mispricing, sorting on AI-disclosure intensity yields a positive risk-adjusted return spread over |
| 120 | −return spread over the full 2010--2024 formation sample. |
195 | +the full 2010--2024 formation sample, in sort and in regression form, that survives winsorization. |
| 121 | \item[H2 (Regime dependence).] If instead AI exposure is repriced only once AI becomes salient, the |
196 | \item[H2 (Regime dependence).] If instead AI exposure is repriced only once AI becomes salient, the |
| 122 | −return spread is small before and large after the late-2022 generative-AI catalyst, and the |
197 | +return spread is small before and large after the late-2022 generative-AI catalyst, the increase |
| 123 | −increase is visible in each post-launch cohort rather than in a single one. |
198 | +is visible in each post-launch cohort rather than in a single one, and the 2022 break date stands |
| |
199 | +out among placebo break dates. |
| 124 | \item[H3 (AI-specificity).] If the post-2022 spread reflects an AI repricing rather than a |
200 | \item[H3 (AI-specificity).] If the post-2022 spread reflects an AI repricing rather than a |
| 125 | −mechanical or market-wide artefact, it appears for AI-related semantic factors but not for unrelated |
201 | +mechanical or market-wide artefact, (a) it appears for AI-related semantic factors but not for |
| 126 | −factors such as ESG, climate, or macro risk, and it is not spanned by a technology-sector factor. |
202 | +unrelated factors such as ESG, climate or macro risk, and (b) it is not spanned by a |
| |
203 | +technology-sector factor. |
| 127 | \item[H4 (Cross-sectional, not within-firm).] If the market repriced \emph{which} firms are |
204 | \item[H4 (Cross-sectional, not within-firm).] If the market repriced \emph{which} firms are |
| 128 | −AI-exposed rather than rewarding incremental wording, the effect is concentrated in the |
205 | +AI-exposed rather than rewarding incremental wording, the association is concentrated in the |
| 129 | −cross-section, attenuates under firm fixed effects, and displays no pre-trend when exposure is held |
206 | +cross-section, attenuates under firm fixed effects, and the event-time profile of a pre-determined |
| 130 | −fixed at its pre-launch level. |
207 | +exposure shows no differential trend before the launch and a positive shift after it. |
| 131 | −\end{description} |
208 | +\item[H5 (Size and projects).] (a) If the post-launch repricing reflects limited attention rather |
| 132 | −\noindent We add a fifth hypothesis that the broad universe makes testable. |
209 | +than a revision of sector cash flows, it is stronger among smaller, less-followed firms than among |
| 133 | −\begin{description}[leftmargin=2.4em,style=nextline] |
210 | +the largest thousand. (b) If the language premium reflects concrete AI activity, it is visible in |
| 134 | −\item[H5 (Size and attention).] If the post-launch repricing reflects limited attention rather than a |
211 | +the firm's own disclosed AI projects as well as in its language. |
| 135 | −revision of sector cash flows, it is stronger among smaller, less-followed firms than among the largest |
| |
| 136 | −thousand, and it is visible in the firm's own disclosed AI projects as well as in its language. |
| |
| 137 | \end{description} |
212 | \end{description} |
| 138 | −\noindent Section~\ref{sec:discussion} summarizes what the Russell~3000 evidence says about each hypothesis. |
213 | +\noindent \Cref{subsec:verdicts} records, clause by clause, what the Russell~3000 evidence says |
| |
214 | +about each hypothesis. |
| 139 | |
215 | |