Augmentation AI is creating new, higher-paid work and drawing students into exposed fields, while automation AI lowers wages and worsens outcomes for low-skilled workers; employers are increasingly hiring AI, data and prediction skills, and returnees from cross-border work suffer a short-lived employment penalty and higher unemployment claims.
The first three chapters of the PhD dissertation analyze the labor-market consequences of AI in the United States and Europe. Chapter four investigates the predictors of cross-border employment and its labor-market impact on returnees. Chapter one examines the effects of AI on the U.S. labor market from 2015 to 2022, distinguishing between automation AI—technologies that substitute for labor—and augmentation AI—technologies that enhance workers' output. I construct novel longitudinal measures of occupational exposure to each type of AI by mapping developer activity on Stack Overflow to occupational descriptions. I also introduce a new measure of emerging work based on successive updates of job titles in O*NET. Using an instrumental-variables strategy based on lagged computer science research intensity, I find that augmentation AI stimulates the creation of new work. Automation AI increases employment but depresses wages. These effects vary across skill groups: automation AI harms low-skilled workers, while augmentation AI raises wages and generates new work primarily for high-skilled occupations. In chapter two, we use 75 million online job postings from four European countries over the 2018–2023 period to investigate how skill and occupational demand have shifted in response to AI. Our analysis leverages data science methods to extract and classify skills from job postings across multiple languages. Instrumenting AI exposure with lagged research intensity in computer science, we document significant growth in demand for AI, Data, and Prediction skills within exposed occupations, alongside a decline in Social skills. Guided by our theoretical framework, the results are consistent with the interpretation that AI, Data, and Prediction are AI-exposed skills, while Judgment, Decision-Making, and Leadership are complementary, and Social skills are substituted. We further document an increased co-occurrence of AI-exposed and complementary skill bundles. Our findings indicate that exposed occupations expand. Chapter three examines how AI exposure influences the selection of Bachelor's programs in the United States from 2010 to 2022. We distinguish between AI used for task automation and AI that complements human work and analyze three margins: aggregate graduation patterns, student demand for education, and college program supply. Using an instrumental-variable strategy based on lagged computer science research intensity, we find that augmentation AI increases graduations in exposed fields, attracts more and higher-ability students, and stimulates program openings. Automation AI has no significant effect on aggregate graduations but is associated with the likelihood of not pursuing postgraduate studies and field-switching after graduation, raises program closures, and reduces new openings. These results indicate that AI-driven labor-market signals propagate upstream to educational decisions, with automation and augmentation generating distinct responses on both the demand and supply sides of higher education. In chapter four, using linked Belgian administrative registers that identify cross-border spells in Luxembourg, we provide individual-level evidence on the determinants of entry and exit and the first causal evidence on post-return outcomes, including returnees' interaction with the residence-country welfare system. Random-forest models reveal sharply nonlinear transition patterns in commuting time, prior employment instability, earnings, and household cross-border exposure. Returnees face a short-run employment penalty that fades with cross-border tenure and time since return. They are also more likely to receive unemployment benefits than comparable stayers, with higher daily benefit levels among recipients. We find no evidence of a sizeable effect on wages following return.
Summary
Main Finding
This PhD dissertation (David Marguerit, 2026) provides a multi‑method empirical assessment of how recent AI development reshapes work, skill demand, education choices, and cross‑border labor flows. Using novel measures of occupational AI exposure (distinguishing automation vs. augmentation), linked administrative and online data, instrumental‑variable identification, and causal machine‑learning, the thesis shows that AI is simultaneously creating "new work" and re‑shaping employment and wages heterogeneously across occupations and skill groups. AI exposure shifts demand toward cognitive/technical and complementary skill bundles, alters college major choice and institutional responses, and interacts with labor mobility in ways that matter for post‑return labor‑market outcomes.
Key Points
- Distinguishing automation vs. augmentation matters: the dissertation constructs separate "Automation AI" and "Augmentation AI" exposure indices (built from Stack Overflow activity and validated with other sources) and demonstrates they have distinct empirical relationships with tasks, job titles, and outcomes.
- New tasks and new job content emerge as AI develops: occupations with higher augmentation exposure show more creation of new task content and alternate job titles over 2015–2022.
- Heterogeneous labor effects:
- AI exposure is associated with reallocation of employment across occupations and within‑occupation task changes. Effects on employment and wages are heterogeneous by occupation and skill group.
- Instrumental variable (CS publications) 2SLS estimates are used to address endogeneity of AI adoption, yielding stronger causal claims about how AI exposure affects new work, employment (log employment), and mean wages.
- Skills demand shifts:
- Analysis of European online job vacancies (2018–2023) using LLM‑based skill extraction shows AI exposure increases demand for certain cognitive/technical skills and bundles that are complementary to AI, while reducing demand for skill bundles that are closer substitutes to automation.
- Theoretical model links AI exposure to production hierarchy and predicts within‑occupation re‑weighting of skill tasks; empirical results broadly support these predictions.
- Human capital and education responses:
- Occupational AI exposure influences college major selection. Students update intentions and choices in response to AI exposure; higher AI automation risk in an occupation is associated with measurable shifts in field‑of‑study outcomes at the bachelor level.
- Educational institutions also respond (openings/closures of programs, curriculum changes) consistent with changing demand signals.
- Labor mobility and AI interactions:
- Using administrative data for Luxembourg, causal machine‑learning methods (prediction and causal ML) identify key predictors of initiating and returning from cross‑border work (CBW) and quantify consequences for post‑return labor‑market states, job quality, and unemployment benefit receipt.
- Cross‑border experience is an important margin of adjustment with heterogeneous returns depending on worker characteristics and history.
Data & Methods
- AI exposure construction:
- Primary innovation: two occupational AI exposure indices (Automation AI and Augmentation AI) derived from technical activity and tagging on Stack Overflow (2010–2022), validated against firm‑level AI adoption and other external measures.
- Instrument: exposure to computer‑science (CS) scientific publications used to construct IVs (regional/occupational shocks in CS R&D).
- Labor market outcomes:
- Employment counts, new task measures (new titles/alternate titles), and wages analyzed at occupation × time granularity; control variables include industry, region, and task content (O*NET) measures.
- Skill demand analysis:
- Large panel of online job vacancies across European countries (Lightcast/other vacancy sources), with LLM‑based extraction and classification of skills into granular skill groups and broader classes; weighting schemes to map vacancies to occupations/industries/locations.
- Instrumental‑variable strategy: local exposure to CS publications as an instrument for occupational AI exposure.
- Human capital analysis:
- Administrative/education datasets on bachelor graduates, intended fields, SAT scores, and program openings/closures; occupational AI exposure mapped into field‑of‑study exposure (state/field level).
- Identification via panel variation and IVs where appropriate; analysis of both intentions and realized field choice.
- Cross‑border work:
- Luxembourg administrative labor‑market data covering worker demographics, employment history, cross‑border links.
- Machine‑learning toolkit: XGBoost and causal ML methods (causal forests / doubly robust learners) for prediction of CBW start/return and for estimating causal effects of returning on subsequent outcomes; extensive validation and partial‑dependence/variable‑importance diagnostics.
- Robustness and validation:
- Extensive appendices report robustness checks: balanced panels, different weighting schemes, outlier removal, alternative tag descriptions, full transition matrices, OLS vs 2SLS, first‑stage diagnostics, and validation of LLM skill extraction against human benchmarks.
Implications for AI Economics
- Measurement contribution: separating automation vs. augmentation exposures (and providing validated indices) improves precision in empirical studies of AI’s labor effects and should be adopted in future research and policy monitoring.
- Policy on skills and training:
- Evidence that AI shifts within‑occupation task mixes and increases demand for complementary cognitive/technical skills argues for targeted upskilling/reskilling programs focused on augmentation complementarities rather than one‑size‑fits‑all approaches.
- Early signals of student responsiveness to AI exposure imply education policy (career guidance, curriculum redesign) can materially affect the supply of human capital aligned with evolving demand.
- Labor‑market adjustment and mobility:
- Cross‑border work is an important margin of adjustment; policies facilitating mobility, recognition of cross‑border experience, and portability of social insurance can influence workers’ ability to adapt to AI‑driven change.
- Distributional concerns:
- Heterogeneous employment and wage effects across occupations/skill groups highlight potential inequality risks. Safety nets, active labor‑market policies, and progressive upskilling investments are needed to mitigate adverse distributional impacts.
- Research and evaluation:
- The dissertation’s combination of new measurement, causal identification, and ML methods offers a template for continued evaluation of AI’s economic effects. Policymakers and researchers should integrate high‑frequency indicators (e.g., technical forum activity, vacancy text analytics) into monitoring frameworks to detect and respond to rapid AI‑driven labor shifts.
If you want, I can (a) extract the specific main empirical coefficients and quantitative magnitudes from the thesis tables (e.g., Tables 1.2–1.5, 2.5.1, 3.4.3, 4.5.*) and summarize them in a short numeric table, or (b) produce a two‑page policy brief tailored for labor‑market or higher‑education policymakers. Which would you prefer?
Assessment
Claims (20)
| Claim | Direction | Outcome | Confidence & Evidence | Details |
|---|---|---|---|---|
| Augmentation AI stimulates the creation of new work in the U.S. (2015–2022). Employment | positive | creation of new work (occupational-level expansion / new tasks/jobs) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI increases employment in the U.S. (2015–2022). Employment | positive | employment (occupation-level employment levels) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI depresses wages in the U.S. Wages | negative | wages |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI harms low-skilled workers. Job Displacement | negative | labor-market outcomes for low-skilled workers (employment and/or wages) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Augmentation AI raises wages primarily for high-skilled occupations. Wages | positive | wages (for high-skilled occupations) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Augmentation AI generates new work primarily for high-skilled occupations. Employment | positive | creation of new work / occupational expansion (high-skilled occupations) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| In four European countries (2018–2023), there is significant growth in demand for AI, Data, and Prediction skills within AI-exposed occupations. Skill Acquisition | positive | demand for AI, Data, and Prediction skills (skill demand in job postings) |
Reading fidelity
high
Study strength
high
|
n=75000000
|
| In those European countries, demand for Social skills declines in AI-exposed occupations. Skill Acquisition | negative | demand for Social skills (skill mentions in job postings) |
Reading fidelity
high
Study strength
high
|
n=75000000
|
| AI-exposed (AI, Data, Prediction) skills pair more frequently with complementary skill bundles (Judgment, Decision-Making, Leadership), i.e., increased co-occurrence of AI-exposed and complementary skills. Skill Acquisition | positive | co-occurrence (bundling) of AI-exposed and complementary skills in job postings |
Reading fidelity
high
Study strength
high
|
n=75000000
|
| AI-exposed occupations expand (grow) in employment/demand in the European sample. Employment | positive | occupation-level expansion (job posting counts / employment demand) |
Reading fidelity
high
Study strength
high
|
n=75000000
|
| Augmentation AI increases Bachelor-degree graduations in AI-exposed fields in the U.S. (2010–2022). Skill Acquisition | positive | graduations (number of Bachelor degrees awarded in exposed fields) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Augmentation AI attracts more and higher-ability students into exposed Bachelor programs. Skill Acquisition | positive | student demand and student ability (quality of entrants) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Augmentation AI stimulates program openings (new Bachelor programs) in exposed fields. Other | positive | program openings (new program counts) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI has no significant effect on aggregate Bachelor graduations. Skill Acquisition | null_result | aggregate graduations (Bachelor degrees) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI is associated with a greater likelihood of not pursuing postgraduate studies and with higher rates of field-switching after graduation. Skill Acquisition | negative | postgraduate enrollment decisions and field-switching after graduation |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Automation AI raises program closures and reduces new program openings. Other | negative | program closures and new program openings (program supply) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Random-forest models (Belgian administrative registers) reveal sharply nonlinear transition patterns predicting entry and exit into cross-border work, with commuting time, prior employment instability, earnings, and household cross-border exposure as strong predictors. Employment | mixed | entry and exit into cross-border employment (transitions) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Returnees face a short-run employment penalty after returning from cross-border work, but this penalty fades with cross-border tenure and with time since return. Employment | mixed | employment (post-return employment probability / employment rate) |
Reading fidelity
high
Study strength
medium
|
not reported
|
| Returnees are more likely than comparable stayers to receive unemployment benefits, and among recipients they receive higher daily benefit levels. Social Protection | positive | unemployment benefit receipt and daily benefit level |
Reading fidelity
high
Study strength
medium
|
not reported
|
| There is no evidence of a sizeable effect on wages following return from cross-border employment. Wages | null_result | wages (post-return wages) |
Reading fidelity
high
Study strength
medium
|
not reported
|