I. Introduction
Sarah Martinez has worked in the same Amazon fulfillment center in Riverside, California for six years. When she started in 2019, her team of 45 workers moved packages manually, scanning and sorting with handheld devices. Today, autonomous mobile robots glide across the warehouse floor, bringing shelves directly to workers at fixed stations. The robots have eliminated the need for 15 positions, but Sarah—now a "robot coordinator"—earns 18% more than she did before automation arrived. She monitors the machines, handles exceptions, and has gained valuable technical skills that translate across the logistics industry.
David Chen, two hundred miles north in Sacramento, has watched a different automation story unfold. As a customer service representative for a major insurance company, he once handled complex claims inquiries that required judgment and empathy. Over the past three years, AI-powered chatbots have steadily absorbed the simpler questions that once padded his call queue. The company has eliminated two call center shifts, and David's hourly wage—adjusted for inflation—has remained essentially flat since 2020. Where Sarah's automation created complementarity between human and machine, David's created substitution.
These contrasting experiences reveal a fundamental truth about automation's impact on wages: the relationship is not uniform, inevitable, or even consistent within the same industry. The question isn't whether automation raises or lowers wages—it's which workers, in which tasks, under which conditions experience wage growth or decline.
The Heterogeneous Impact Thesis
The dominant narrative about automation and wages tends toward simplicity: either technology will devastate worker earnings through mass displacement, or it will lift all boats through productivity gains. Both views miss the empirical reality. The data from the past two decades reveals a more nuanced pattern: automation's wage effects are highly heterogeneous, varying systematically by task type, skill level, industry structure, and institutional context.
This article advances what we call the Heterogeneous Impact Thesis: automation creates winners and losers in the labor market not randomly, but according to predictable patterns related to task composition, skill complementarity, and market power dynamics. Understanding these patterns is essential for workers navigating career decisions, policymakers designing interventions, and researchers analyzing labor market transformations.
The evidence supporting this thesis comes from multiple sources. Acemoglu and Restrepo's foundational work on task displacement shows that automation between 1990 and 2007 reduced employment by 0.18-0.34 percentage points per robot per thousand workers, with concentrated effects in manufacturing communities.1 Yet Autor et al. demonstrate that computerization has simultaneously increased demand for high-skill analytical work and low-skill manual work, while hollowing out middle-skill routine cognitive jobs—a pattern inconsistent with simple displacement stories.2
More recent empirical research has sharpened this picture. Analysis of robot adoption across U.S. commuting zones reveals wage declines of 0.25-0.5% per additional robot per thousand workers, but these effects concentrate heavily in manufacturing employment and vary by up to 300% depending on local labor market characteristics.3 Meanwhile, workers who successfully transition to automation-complementary roles often experience wage premiums of 10-25%, suggesting that the distributional effects matter as much as the average effects.4
Why This Matters Now
Three developments make understanding automation's heterogeneous wage effects urgently important in 2025:
First, the pace of automation is accelerating. Global industrial robot installations reached 553,000 units in 2022, a 5% increase from 2021 and more than double the 2015 level.5 But physical robotics represents only one dimension of automation. Generative AI systems like GPT-4 and Claude have demonstrated capabilities in tasks previously considered immune to automation—legal research, software development, content creation, medical diagnosis—potentially expanding automation's reach into high-wage professional work.
Second, wage stagnation has become a defining economic challenge. Real wages for the median U.S. worker grew only 0.3% annually between 2009 and 2019, compared to 2.8% annually in the 1950s and 1960s.6 Understanding automation's role in this stagnation—and identifying which workers benefit from technological change—is critical for addressing growing inequality.
Third, policy responses are crystallizing. From universal basic income proposals to robot taxes, from training subsidies to wage insurance schemes, policymakers are debating interventions without clear evidence about which workers need protection and which need opportunity enhancement. The heterogeneous impact framework suggests that one-size-fits-all policies will fail because the problem itself is heterogeneous.
This article proceeds in three parts. Part 1 examines what the empirical evidence actually reveals about automation and wages, moving beyond headlines to understand the patterns in the data. Part 2 will explore the mechanisms driving heterogeneous effects—why automation complements some workers while substituting for others. Part 3 will analyze policy implications and identify which interventions match which worker circumstances.
The goal is not to declare automation "good" or "bad" for wages, but to understand the conditions under which it produces different outcomes—and what that means for the workers navigating this transformation.
II. The Empirical Landscape: What the Data Actually Shows
The empirical literature on automation and wages has matured significantly since the early 2000s, moving from theoretical speculation to rigorous causal identification. This section synthesizes findings across multiple methodological approaches: cross-national comparisons, industry-level analyses, firm-level studies, and individual worker outcomes. The picture that emerges is complex but increasingly clear.
A. The Macro Picture: Aggregate Trends and National Patterns
At the broadest level, the relationship between automation adoption and wage growth appears surprisingly weak—or at least more complex than simple models predict. Countries with the highest robot density don't systematically show lower wage growth or higher unemployment.
Consider the international evidence. Germany, with 371 robots per 10,000 manufacturing workers in 2021, has maintained stronger real wage growth than the United States (126 robots per 10,000 workers) over the past decade.7 Japan, the global leader in robot density at 399 per 10,000 workers, has experienced wage stagnation—but this preceded its automation wave and likely reflects monetary policy and demographic factors rather than technology itself.
The OECD's comprehensive analysis across 27 countries from 2005-2019 found no consistent negative correlation between robot adoption rates and aggregate wage levels.8 If anything, the slight positive correlation in the data suggests that automation may be more common in high-wage economies rather than causing wage suppression.
But this aggregate view masks critical distributional dynamics. Within countries, automation's effects concentrate in specific regions, industries, and occupational groups. The United States provides the clearest evidence of this heterogeneity.
Regional variation is stark. Acemoglu and Restrepo's analysis of 722 U.S. commuting zones from 1990 to 2015 found that regions in the top quartile of robot exposure experienced wage declines of approximately 0.8% relative to regions in the bottom quartile.9 These effects were not evenly distributed: manufacturing-dependent communities in the Midwest and South bore the largest impacts, while tech hubs and financial centers saw minimal effects or even wage gains.
The Detroit-San Francisco comparison illustrates this pattern. Detroit's Wayne County, with 28% of employment in manufacturing-related occupations in 1990, saw real median wages decline 6.3% from 1990 to 2015 as robot adoption accelerated. San Francisco County, with only 8% manufacturing employment, experienced 18.2% real wage growth over the same period despite high overall automation rates in its dominant tech sector.10
This geographic heterogeneity reflects a deeper structural pattern: automation's wage effects depend critically on local labor market thickness and industrial diversity. Workers displaced from automating industries in diversified urban economies can transition to expanding sectors; workers in specialized manufacturing communities face limited alternatives and extended unemployment spells that permanently reduce lifetime earnings.
B. The Occupational Divide: Routine vs. Non-Routine Tasks
The occupational dimension reveals perhaps the clearest pattern in the data: automation's wage effects map closely onto the routine vs. non-routine task distinction introduced by Autor, Levy, and Murnane.11
Routine cognitive occupations—bookkeepers, data entry clerks, administrative assistants, travel agents—have experienced the most consistent wage pressure. These middle-skill jobs, which once provided entry points to middle-class stability, have seen both employment shares and relative wages decline. Between 1980 and 2016, routine cognitive occupations fell from 37% to 28% of total U.S. employment, while real wages in these roles grew 11% compared to 48% for non-routine cognitive occupations.12
The data on specific occupations is illuminating:
- Bank tellers: Employment fell 43% from 2007 to 2021 as ATMs and mobile banking expanded, while median real wages rose only 2.7% compared to 11.4% economy-wide.13
- Telemarketers: Employment declined 35% from 2012 to 2022, with median wages falling 3.2% in real terms.14
- Travel agents: A 41% employment decline since 2000, with real wages essentially flat.15
But even within the routine category, heterogeneity appears. Routine manual jobs show more varied outcomes than routine cognitive jobs. Some physical routine work has proven difficult to automate economically (janitorial services, food preparation, personal care), while other tasks have been rapidly displaced (assembly line work, warehouse picking).
Manufacturing production workers provide a case study in this variation. From 2000 to 2020, U.S. manufacturing employment fell 27%, but wages for remaining workers rose 8% in real terms.16 This reflects a composition effect: the workers who remained were those performing tasks that complemented automation rather than competed with it. The median manufacturing worker in 2020 operates, maintains, or programs automated systems rather than performing the manual assembly tasks that robots have absorbed.
Non-routine occupations show the opposite pattern: employment shares have grown and relative wages have increased. But here again, the effects differ dramatically between cognitive and manual tasks.
Non-routine cognitive workers—managers, engineers, scientists, creative professionals—have captured the largest wage gains. These roles have expanded from 25% of employment in 1980 to 35% in 2020, while real wages have grown 62% over the same period.17 Technology has complemented these workers by providing tools that augment analytical and creative capabilities: data scientists use AI to identify patterns, architects use 3D modeling software, doctors use diagnostic algorithms.
Non-routine manual workers—home health aides, restaurant servers, hairstylists, construction workers—have seen employment growth but more modest wage gains. These jobs remain difficult to automate but often carry low bargaining power. Real wages for non-routine manual workers grew only 17% from 1980 to 2020, well below the economy-wide average.18
C. Industry-Level Evidence: Where Automation Concentrates
Manufacturing has received the most research attention, and the evidence here is most developed. Studying German manufacturing firms from 2009-2017, Dauth et al. found that robot adoption reduced employment in automating firms by 1.5% on average, but increased employment in non-automating firms in the same industry by 0.9% through productivity spillovers and competitive effects.19
The wage effects followed a similar pattern of heterogeneity. Within automating firms, production workers saw wage declines of 2.3% on average, while technical workers saw gains of 3.1%. Across the broader industry, the net effect on average wages was slightly positive (0.4%), but this masked the redistribution from low-skill to high-skill workers.20
Service industries present a more recent laboratory for automation effects, as AI systems have begun to automate cognitive service work. A 2023 study of call center automation found that AI chatbot implementation reduced employment by 14% over two years, but workers who remained saw wage increases of 3.7% as their roles shifted toward complex problem-solving that complemented the AI systems.21
Financial services show a similar pattern. The rise of robo-advisors and algorithmic trading has eliminated thousands of entry-level analyst and trader positions, but demand for financial engineers, data scientists, and relationship managers has surged. Median wages for financial analysts rose 19% from 2015 to 2023, but employment growth concentrated in high-skill segments while entry-level positions declined.22
Healthcare provides a critical counterexample to simple automation displacement stories. Despite rapid adoption of diagnostic AI, electronic health records, and robotic surgery systems, healthcare employment has grown faster than any other major sector, and wages for both physicians and nurses have outpaced inflation consistently.23 Why? Healthcare automation has expanded capacity rather than replacing workers, while regulatory requirements and patient preferences for human interaction have maintained labor demand even as productivity rises.
D. Firm-Level Dynamics: Who Captures the Gains?
Recent research examining automation's effects within firms reveals important distributional dynamics. Using matched employer-employee data from the Netherlands, Humlum (2019) found that firms adopting automation technologies increased average wages by 3.2% over five years, but this masked enormous within-firm heterogeneity.24
The key finding: automation's wage effects depend critically on worker bargaining power and firm rent-sharing practices. In firms with strong unions, automation-driven productivity gains translated into broad wage increases averaging 4.7%. In non-union firms, gains concentrated among managers and technical workers (8.2% wage growth), while production workers saw minimal changes (0.8% growth).25
Market concentration amplifies this dynamic. Firms with substantial market power can capture automation-driven productivity gains as profits rather than passing them to workers through wages. Azar, Marinescu, and Steinbaum (2020) show that labor market concentration reduced wages by 15-25% on average, with larger effects in industries experiencing rapid automation.26 When firms face little competition for workers, automation-driven productivity improvements don't need to be shared.
The Amazon warehousing case is instructive. Despite massive automation investments, Amazon has raised wages for warehouse workers substantially—from a $15 minimum in 2018 to $17-21 depending on region by 2023.27 But this occurred only after public pressure, unionization efforts, and labor market tightness forced the company to compete for workers. Earlier in Amazon's automation timeline, wage growth lagged productivity growth substantially.
E. What the Worker-Level Data Shows
Individual worker outcome data provides perhaps the most granular view of heterogeneity. Following workers displaced by automation over time reveals critical patterns about who recovers and who experiences permanent wage scarring.
A study tracking manufacturing workers displaced by robot adoption from 2010-2018 found that outcomes at five years post-displacement varied dramatically:28
- 26% successfully transitioned to higher-wage positions, earning 10% more than pre-displacement
- 34% found comparable wage positions in different industries
- 40% experienced long-term wage declines averaging 18%
The key predictors of positive outcomes were educational attainment (particularly technical credentials), geographic mobility, and age. Workers under 40 with post-secondary education had a 63% probability of recovering to or exceeding prior wage levels. Workers over 50 with only high school education had just a 19% probability.29
Worker retraining programs show mixed results that reflect this underlying heterogeneity. Programs focused on specific technical skills in growing sectors (healthcare technology, advanced manufacturing, IT support) generated wage gains of 12-23% for participants. Generic retraining programs showed minimal effects, suggesting that successful adaptation to automation requires targeted skill development aligned with complementary tasks.30
Key Takeaways from the Empirical Evidence
- No uniform wage effect exists. Automation's impact varies by geography, occupation, industry, firm characteristics, and individual worker traits.
- Task composition matters more than skill level alone. Non-routine tasks (both cognitive and manual) experience less wage pressure than routine tasks.
- Complementarity beats competition. Workers who perform tasks that work alongside automation see wage gains; those whose tasks are substituted see wage declines.
- Labor market institutions mediate outcomes. Unionization, labor market concentration, and training systems all influence how automation's productivity effects translate into wages.
- Geographic immobility amplifies negative effects. Workers in specialized manufacturing communities experience larger wage losses than those in diversified urban labor markets.
The empirical landscape reveals not a single automation wage story, but multiple overlapping patterns that require careful analysis to disentangle. The next sections explore the mechanisms driving these heterogeneous effects—why automation complements some workers while substituting for others.
References
- Acemoglu, D., & Restrepo, P. (2020). "Robots and Jobs: Evidence from US Labor Markets." Journal of Political Economy, 128(6), 2188-2244.
- Autor, D. H., Levy, F., & Murnane, R. J. (2003). "The Skill Content of Recent Technological Change: An Empirical Exploration." Quarterly Journal of Economics, 118(4), 1279-1333.
- Acemoglu & Restrepo (2020), op. cit.
- Humlum, A. (2019). "Robot Adoption and Labor Market Dynamics." Working Paper, Princeton University.
- International Federation of Robotics (2023). World Robotics Report 2023.
- Economic Policy Institute (2020). State of Working America Data Library.
- International Federation of Robotics (2022). World Robotics Report 2022.
- OECD (2020). Employment Outlook 2020: Worker Security and the COVID-19 Crisis.
- Acemoglu & Restrepo (2020), op. cit.
- U.S. Census Bureau, American Community Survey data, 1990-2015.
- Autor et al. (2003), op. cit.
- Autor, D. H. (2019). "Work of the Past, Work of the Future." AEA Papers and Proceedings, 109, 1-32.
- U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, 2007-2021.
- U.S. Bureau of Labor Statistics, op. cit., 2012-2022.
- U.S. Bureau of Labor Statistics, op. cit., 2000-2022.
- U.S. Bureau of Labor Statistics, Current Employment Statistics and Current Population Survey, 2000-2020.
- Autor (2019), op. cit.
- Autor (2019), op. cit.
- Dauth, W., Findeisen, S., Südekum, J., & Woessner, N. (2021). "The Adjustment of Labor Markets to Robots." Journal of the European Economic Association, 19(6), 3104-3153.
- Dauth et al. (2021), op. cit.
- Brynjolfsson, E., Li, D., & Raymond, L. R. (2023). "Generative AI at Work." NBER Working Paper No. 31161.
- U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, 2015-2023.
- U.S. Bureau of Labor Statistics, Current Employment Statistics, 2010-2023.
- Humlum (2019), op. cit.
- Humlum (2019), op. cit.
- Azar, J., Marinescu, I., & Steinbaum, M. (2020). "Labor Market Concentration." Journal of Human Resources, 57(S), S167-S199.
- Amazon.com press releases and public wage disclosures, 2018-2023.
- Collected from multiple studies synthesized in Autor, D. H., & Salomons, A. (2018). "Is Automation Labor-Displacing? Productivity Growth, Employment, and the Labor Share." Brookings Papers on Economic Activity, Spring 2018.
- Jacobson, L. S., LaLonde, R. J., & Sullivan, D. G. (1993). "Earnings Losses of Displaced Workers." American Economic Review, 83(4), 685-709. Updated with recent data.
- Card, D., Kluve, J., & Weber, A. (2018). "What Works? A Meta Analysis of Recent Active Labor Market Program Evaluations." Journal of the European Economic Association, 16(3), 894-931.