How Will Cable Operators Re-Architect to Add Upstream Bandwidth?

Hybrid fiber coax upgrades intended to increase upstream bandwidth can take a number of forms. Shrinking the serving areas; switching to fiber-to-home and re-architecting the network for different frequency plans are the typical choices. 

For operators who want to delay the shift to FTTH, moving from the standard HFC low-split design, and substituting a mid-split or high-split frequency plan, are the two architectural choices other than shrinking the fiber node serving areas or moving to an entirely-new FTTH network. 

As always, incrementalism is favored. Comcast appears to prefer the mid-split option, while Charter seems to be leaning towards a more-radical high-split approach. In terms of capital investment, the mid-split choice might be a shorter-window bridge to FTTH, while high-split might allow a longer window before FTTH is required. 

More symmetrical bandwidth is a large part of the thinking.  

DOCSIS 4.0 is going to force decisions about which path to take to support symmetrical multi-gigabit-per-second speeds of as much as 10Gbps downstream and up to 6 Gbps upstream.

source: Comscope 

Hybrid fiber coax networks still use frequency division, separating upstream and downstream traffic by frequency. So when a cable operator contemplates adopting mid-split or high-split designs, there are implications for active and passive network elements, especially for the more-radical high-split design. 

At this point, executives also will ask themselves whether, if radical changes are required, whether it would not be better to simply switch to fiber-to-home. 

source: Broadband Library 

Our notions of mid-split and high-split frequency plans have shifted a bit over the years, as total bandwidth has grown beyond 450 MHz up to 1.2 GHz. A designation of “mid-split”  made more sense in an era where total bandwidth was capped at about 450 MHz or 550 MHz. In those days, 108 MHz to 116 MHz of return bandwidth was perhaps 42 percent of the usable bandwidth. 

Hence the “mid-split” designation. 

Likewise for high-split designations, where as much as 186 MHz was designated for the return path, the return bandwidth represented as much as 67 percent of usable bandwidth on a 450-MHz coaxial cable system. 

source: Broadband Library  

Definitions remain, though with some new standardization of return bandwidths. “Mid-split” now features 85 MHz of return bandwidth, while “high-split” offers 204 MHz of upstream bandwidth. 

source: Broadband Library  

“Ultra-high-split” designs also are being investigated, where the upstream spectrum’s upper frequency limit can be 300 MHz, 396 MHz, 492 MHz, or 684 MHz, says Ron Hranac, consulting engineer. 

What remains true is that the ability to wring more performance out of hybrid fiber coax plant has proven more robust than many expected a decade ago. 

Also being considered are full duplex designs that swap time division for frequency division multiplexing. That is an option for DOCSIS 4.0 networks, and is a break from the frequency division HFC has used.

source: CableLabs 

Full duplex networks would allow the upstream and downstream traffic to use the same spectrum at the same time. That would require an HFC upgrade to a node-plus-zero amplifiers” design that is similar to fiber to the curb. The drop to the user location still uses coaxial cable, but without any radio frequency amplifiers. 

source: CableLabs 

The whole point of all these interventions is to supply more upstream or return bandwidth than HFC presently provides. 

source: Qorvo

Cable operators are a practical bunch, and will prefer gradualism when possible. So one might hypothesize that either mid- or high-split designs will be preferred. 

Next HFC Upgrade Will be Driven by Business Assumptions

Cable operators and mobile operators share one business commonality: capacity improvements hinge on the availability of spectrum and the degree of frequency reuse (smaller cells or serving area sizes). 

Both mobile and cable operators can effectively boost capacity by using different modulation techniques as well. But cable operators face a bigger problem, architecturally. “At some point” in the future a shift to fiber to home designs seems inevitable. 

But there are many ways to upgrade the hybrid fiber coax network before then, with varying degrees of capital investment and complexity, as well as capacity improvements. So each upgrade path embeds assumptions about what the market will require in terms of both upstream and downstream capacity , and for how long. 

DOCSIS 4.0 is going to force decisions about which path to take to support symmetrical multi-gigabit-per-second speeds of as much as 10Gbps downstream and up to 6 Gbps upstream.

source: Comscope 

Hybrid fiber coax networks still use frequency division, separating upstream and downstream traffic by frequency. So when a cable operator contemplates adopting mid-split or high-split designs, there are implications for active and passive network elements, especially for the more-radical high-split design. 

At this point, executives also will ask themselves whether, if radical changes are required, whether it would not be better to simply switch to fiber-to-home. 

source: Broadband Library 

Our notions of mid-split and high-split frequency plans have shifted a bit over the years, as total bandwidth has grown beyond 450 MHz up to 1.2 GHz. A designation of “mid-split”  made more sense in an era where total bandwidth was capped at about 450 MHz or 550 MHz. In those days, 108 MHz to 116 MHz of return bandwidth was perhaps 42 percent of the usable bandwidth. 

Hence the “mid-split” designation. 

Likewise for high-split designations, where as much as 186 MHz was designated for the return path, the return bandwidth represented as much as 67 percent of usable bandwidth on a 450-MHz coaxial cable system. 

source: Broadband Library  

Definitions remain, though with some new standardization of return bandwidths. “Mid-split” now features 85 MHz of return bandwidth, while “high-split” offers 204 MHz of upstream bandwidth. 

source: Broadband Library  

“Ultra-high-split” designs also are being investigated, where the upstream spectrum’s upper frequency limit can be 300 MHz, 396 MHz, 492 MHz, or 684 MHz, says Ron Hranac, consulting engineer. 

What remains true is that the ability to wring more performance out of hybrid fiber coax plant has proven more robust than many expected a decade ago. 

Also being considered are full duplex designs that swap time division for frequency division multiplexing. 

source: CableLabs  

Each technology upgrade path has business implications, especially the cost to upgrade HFC in some way without shifting to FTTH. The other assumption is the competitive environment and how long each alternative upgrade can support the expected business model.

Gigabit Networks Will Destabilize the ISP Market

There are times in the global communications business when stability is the main trend. The first 125 years of telecom history were such times of fundamental stability.

But there are other times when instability and change are the main trends. That might have been said to be the case when global privatization and deregulation happened in the 1980s and 1990s. And instability now is growing with the maturation of voice and the rise of Internet access and mobility as anchor services.

Some might argue growing instability is what we will see over the next decade. Consider only the impact of symmetrical gigabit Internet access service. Quantitative change is not the only issue. Qualitative competitive implications will exist for contestants using different network topologies and access media.

Consider cable operator frequency plans and use of hybrid fiber coax, for example. Executives typically argue that HFC can be upgraded incrementally to support future bandwidths of that sort.

To support gigabit networks, it is argued, fiber is simply extended deeper in the access network, decreasing serving area size by about an order of magnitude, creating the same sorts of advantages mobile operators gain by using a fixed amount of spectrum in a cellular configuration.

Though the least disruptive, such an upgrade might feature per-user peak bandwidth of 100 Mbps, still an order of magnitude slower than Google Fiber’s 1 Gbps, symmetrical. Some say only the high-split and new top-split frequency plans, all featuring more fiber, will support gigabit speeds.

But some might suggest it would be easier to overlay some sort of fiber to home capability than to dramatically change frequency plans now commonly used by U.S. cable operators to support symmetrical gigabit Internet access services. At least so far, most cable executives deem that too expensive an approach.

Though three different frequency plans (low split, mid-split, high split) have been available for decades, virtually all cable operators use the low split plan. Basically, that means frequencies up to 54 MHz are reserved for return signals, while all the rest of the bandwidth up to about 850 MHz is used to support downstream communications and services.

But even traditional “mid-split or high-split networks are not symmetrical. The mid-split frequency plan increases return bandwidth up to about 85 MegaHertz. The high-split network increases return bandwidth to about 200 MHz. The new top-split network offers support for gigabit speeds gigabit speeds.

For cable operators, as for others using radio frequency networks,  the challenge symmetrical gigabit services pose is not simply quantitative (more) but qualitative (equal split networks are needed).

Big Strategic Shift for FTTH?

The strategic context for U.S. home broadband is evolving. For two decades, cable TV operators have been able to consistently maintain installed base share close to 70 percent, in most years getting the majority to all of the net new account additions. 

That remains the case in 2021, as cable continues to hold its installed base lead and also continues to win the net new additions battle.  

All that now seems set for change, though. The biggest change is an up- tempo pace of fiber to home conversions by telcos. But new 5G high-bandwidth fixed wireless offerings should claim some share as well. 

source: New Street Research 

Also important is the way some telcos are positioning their upgrades. In the past, they might have been content to match cable offers. Now some are aiming to surpass cable offers, with symmetrical upstream bandwidth a weapon.  

Frontier Communications, for example, is preparing rollout of a 2-Gbps offer, in addition to its standard 1-Gbps and entry-level 500-Mbps offers. That will likely feature symmetrical bandwidth. 

To be sure, cable is working on its own 10-Gbps capabilities, as well as methods to add more upstream bandwidth. But many of those solutions are not graceful upgrades from the existing hybrid fiber coax platform. The choice is whether to revamp HFC in significant ways or switch to FTTH as the replacement. 

More upstream bandwidth could be provided, to some extent, by pushing fiber deeper into the HFC network. Alternatively, cable operators can swap frequency plans, moving to mid-split or high-split designs. But all those moves require disruption of the physical plant, and cannot be accomplished by swapping out end user gear, as has been the case in the past. 

And any shift to fiber deeper networks, mid-split or high-split architectures (or two of the above) essentially delays an eventual shift to FTTH in any case, many would argue. So the decision comes down to “spend less now, but more in the long term, while undertaking a major network disruption twice” or “spend more now, and be done with it, and only disrupt operations once.” 

The larger point is that upgrading to FTTH comes with other choices that can confer advantage. Bandwidth can be symmetrical, or not. Bandwidth can top out at various levels: higher or relatively lower. And retail pricing, terms and conditions also make a difference. 

Much thinking now seems to be going into how to tweak those parameters to gain advantage over cable operator competitors. Many might assume FTTH means gigabit speeds. It does not. FTTH is physical media. Service providers still must decide how much bandwidth they want those networks to supply. 

Historically, FTTH might have meant speeds in the hundreds of megabits. Some U.S. FTTH networks installed in the mid-1990s to late 1990s offered speeds only up to 10 Mbps. User experience might be an order of magnitude less than advertised, however, even on FTTH platforms.  

What seems to be changing is a willingness to leverage FTTH to gain a speed advantage. 

 

“Our network is already 10-gig capable end-to-end, so we can carry on driving up speed tiers, as demand requires, in a very low-cost, very quick way, again, in a way that cable can't, says Nick Jeffery, Frontier Communications CEO. 

But that only matters if most Frontier customers can buy the service. 

“Our plan (is) to reach a total of five million fiber locations by the end of 2022 and 10 million locations by the end of 2025,” says Nick Jeffery, Frontier Communications CEO. 

Frontier has 15.2 million locations passed, so 10 million total FTTH passings means about 66 percent of the potential customer base would be able to buy FTTH services. 

Of course, a higher installed base does take time. “Our 2020 expansion cohort continues to show strong penetration of 30 percent at the 12-month mark,” says Jeffery, though noting that figure is based on a small sample. 

“For the overall build plan, we continue to expect a 15 percent to 20 percent penetration rate at the 12-month mark, and with penetration continuing to rise in subsequent years toward a terminal penetration of 45 percent,” he added. 

Government subsidies also are expected to improve the business case for FTTH and other high-speed services, as they are increasing substantially. 

George Ford, economist at the Phoenix Center for Advanced Legal and Economic Public Policy Studies, argues that about 9.1 million U.S. locations are “unserved” by any fixed network provider. 

Though specifics remain unclear, it is possible that a wide range of locations might see their deployment costs sliced by $2,000 or more. Lower subsidies would enable many more locations to be upgraded to FTTH, for example: not the unserved locations but possibly also many millions of locations that have been deemed “not feasible” for FTTH.

Much hinges on the actual rules that are adopted for disbursement. Simple political logic might dictate that aid for as many locations as possible is desirable, though many will argue for targeting the assistance to “unserved” locations. 

But there also will be logic for increasing FTTH services as widely as possible, which will entail smaller amounts of subsidy but across many millions of connections. The issue is whether to enable 50 million more FTTH locations or nine million to 15 million of the most-rural locations. 

Astute politicians will instinctively prefer subsidies that add 65 million locations (support for the most-rural locations plus many other locations in cities and towns where FTTH has not proven obviously suitable). 

The issue is the level of subsidy in various areas. 

“According to my calculations, if the average subsidy is $2,000 (which is the average of the RDOF auction), then the additional subsidy required to reach unserved households is $18.2 billio,” Ford argues. “If the average subsidy level is $3,000, then $22.8 billion is needed. And at a very high average subsidy of $5,000, getting broadband to every location requires approximately $45.5 billion.”

The point is that, compared to the business case 20 years ago, FTTH is better in a number of ways. Strategically, copper facilities simply are outmoded. Any fixed network operator clinging to that platform is destined for death. 

Financially, the older triple-play model--with its cost structure and complexity--now is out of favor. The new model is based on home broadband: the sole service for an independent ISP, and the growth driver for an incumbent telco. 

Oddly enough, the older justification for FTTH--that it allows telcos to support many services--now is eclipsed by the simple value of internet access. The value of the “do anything” platform still remains. 

Only these days the primary value driver for an incumbent telco or independent ISP is “access.” Voice or video entertainment might contribute additional revenue and value, but where there is a choice, new providers simply build on home broadband, leaving apps to be supplied by others. 

All that is a big potential change.

AI Will Eliminate Whole Industries, Not Just Some Jobs

Virtually all observers believe artificial intelligence is going to eliminate some jobs, in line with the ability AI might have to automate key job functions. The attrition could come because higher output can be achieved using fewer people, perhaps more so than because AI completely eliminates a particular job role. 

podcast of this content

But that is not even the most important "threat." Whole industries can disappear when a general-purpose technology appears, and AI is likely to be a GPT.

Industry	Disrupted by	New Industries/Roles
Horse-drawn carriage manufacturing	Internal combustion engine	Automobile manufacturing, transportation services
Typewriter manufacturing	Personal computer	Computer hardware and software manufacturing, word processing services
Film photography	Digital photography	Digital camera manufacturing, digital imaging services
Record stores	Digital music distribution (MP3, streaming)	Music streaming services, digital music production
Travel agents	Online travel booking websites	Travel technology companies, online travel booking services
Traditional retail	E-commerce	Online retail, logistics and delivery services

If AI does prove to be a general-purpose technology on the pattern of agriculture, steam power, the internal combustion engine, computing or electricity, that is inevitable. A look at the impact of various computing technologies, from personal computers to AI, illustrate the point, but huge changes in labor forces have always accompanied the emergence of a new GPT. 

Agriculture allowed humans to settle, rather than living as hunters and gatherers, creating the underpinnings for economic surplus that in turn enabled population growth, job specialization and settlements that enabled  the development of art, writing, legal systems, mathematics, new tools,  medicine and more-complex social structures. 

Study Title	Date	Publisher	Key Findings
The Second Machine Age: Work, Progress, and Prosperity in a Time of Brilliant Technologies	2014	W. W. Norton & Company	Discusses how technologies like AI, robotics, and personal computers have automated routine jobs in clerical, manufacturing, and administrative sectors, while creating new roles in software development, IT management, and creative industries.
The Race between Education and Technology	2014	National Bureau of Economic Research (NBER)	Shows how general-purpose technologies, particularly computers, have reduced demand for middle-skill jobs (clerks, machine operators) and increased demand for high-skill (software engineers, data analysts) and low-skill jobs (service workers).
Technological Change and the Labor Market: A Survey	2017	Journal of Economic Surveys	Examines how the introduction of GPTs (such as AI, automation, and IT) has led to job polarization, with job losses in low-to-middle skill categories and gains in high-skill, technology-oriented positions, such as data scientists, AI researchers, and cybersecurity experts.
Automation, Jobs, and the Future of Work	2019	International Monetary Fund (IMF)	Reviews global trends in automation and AI, showing how GPTs have reduced the need for routine manual and cognitive jobs (e.g., typists, cashiers, machine operators), while increasing demand for jobs in tech, management, and highly skilled service sectors.
AI, Robotics, and the Future of Work	2018	Brookings Institution	Analyzes how AI and robotics, as general-purpose technologies, have transformed sectors like manufacturing, retail, and logistics by displacing low-skill jobs, but creating high-skill roles in programming, system analysis, and tech support.
Digital Transformation and the Future of Jobs	2020	World Economic Forum	Finds that GPTs like AI, blockchain, and the Internet of Things (IoT) have contributed to job displacement in traditional sectors like agriculture and manufacturing, while creating job opportunities in digital and tech sectors, such as cloud computing and cybersecurity.
The Impact of Information Technology on Labor Demand	2019	Journal of Economic Surveys	Examines the role of IT and general-purpose technologies in reshaping labor demand. It finds that routine jobs in finance, clerical work, and manual labor have declined, while demand for IT professionals, software developers, and project managers has risen.
How AI and Robotics are Transforming Labor Markets	2020	European Central Bank (ECB)	Demonstrates that AI and robotics have led to the disappearance of low-wage, routine manual jobs, and the growth of tech jobs in AI systems, machine learning, data processing, and AI ethics. Also highlights growing demand for high-skilled healthcare roles enabled by AI.
The Effects of Automation on Jobs and Wages: A Global Perspective	2023	OECD	Highlights that GPTs like AI and robotics have not only automated routine jobs in manufacturing and services but also created new job categories in software development, healthcare technology, and digital infrastructure management.
Automation and the Shift in Labor Markets: Evidence from AI and Robotics	2021	Review of Economics and Statistics	Provides evidence that AI and robotics have led to the shrinking of low-skilled jobs (e.g., assembly line workers) while new opportunities have emerged in tech-heavy fields like AI programming, cybersecurity, and data analysis, where skill requirements are much higher.
Technology, Jobs, and Inequality: A Survey of the Evidence	2018	Economic Policy Institute	Analyzes how the adoption of GPTs, including AI and automation, leads to job polarization, creating a split between low-wage, low-skill jobs in the service sector and high-wage, high-skill jobs in tech fields like cloud computing, data science, and AI.
Work in the Age of AI: The Impact of Automation and AI on Job Categories	2022	MIT Technology Review	Examines the effects of AI-driven GPTs on job categories, showing a decline in traditional roles such as truck drivers and retail workers, while new categories like AI ethics officers, machine learning trainers, and drone operators emerge.
The Future of Jobs in the Age of Automation	2017	McKinsey Global Institute	Explores how general-purpose technologies like automation and AI displace routine work (e.g., cashiers, clerks), but open up new career categories, particularly in fields such as AI system design, data analytics, and machine maintenance.
The Economic Impact of Automation and AI	2021	Stanford Center for Digital Economic Studies	Shows that GPT adoption has led to a shift in employment patterns: many low-skill roles have been automated (e.g., assembly line workers, clerks), while there is an increased demand for data scientists, digital marketers, and machine learning engineers.

So concerns about changes in job composition of the labor force are realistic, if quite possibly inevitable. U.S. dockworkers recently conducted a strike among which key demands included a complete ban on automation of dock work. Discussions about that portion of new contracts remain active, but the larger point is that demands by workers to ban the use of machinery of all types has arguably slowed, but never stopped, the deployment of new technology based on a GPT that automated formerly-human labor. 

Personal computers, for example, did not so much eliminate whole jobs as make possible the ability of each worker to produce some output that formerly might have been created by others (people write their own emails and documents, where in the past stenographers would have done so. 

PCs democratized access to tools that allowed workers at all levels to produce output that once would have been handled by others, such as document production, data entry, analysis, and design.

Before PCs became widespread, tasks like document production, data processing, and basic design were often handled by specialized staff such as secretaries, typists, clerks, and graphic designers. “Desktop publishing,” for example, was an early use case for Apple computers. 

As always, new jobs arose, as well. 

Sector/Occupation	Job Function Pre-PC	Job Function Post-PC	Change in Demand
Clerical/Administrative	Typist, Data Entry Clerk, Secretary	Office Manager, Executive Assistant, Office Coordinator	Decreased
Accounting/Finance	Bookkeeper, Ledger Clerk, Accounts Clerk	Financial Analyst, Accounting Software Specialist	Decreased
Manufacturing	Manual Laborer, Assembly Line Worker, Machine Operator	CNC Operator, Maintenance Technician, Robotics Specialist	Decreased
Retail	Inventory Clerk, Cashier, Stock Clerk	E-commerce Manager, Inventory System Analyst	Decreased
IT and Technology	None	Software Developer, Systems Administrator, IT Support	Increased
Customer Service	Telephone Operator, Customer Service Representative	Help Desk Technician, Customer Support via Online Platforms	Increased
Marketing and Sales	Sales Clerk, Telemarketer, Market Research Assistant	Digital Marketing Specialist, Social Media Manager	Increased
Education	School Secretary, Paper-Based Research Assistant	EdTech Specialist, E-learning Coordinator, Curriculum Developer	Increased
Health Services	Medical Records Clerk, Billing and Coding Clerk	Medical Data Analyst, Health IT Specialist, Telemedicine Support	Increased
Logistics/Transportation	Shipping Clerk, Inventory Handler, Dispatcher	Supply Chain Analyst, Logistics Software Manager	Increased

At a high level, most observers might agree that AI poses similar sorts of upside and downside, from the standpoint of jobholders. New jobs are going to be created, but some existing jobs will likely decrease in number. In that sense, we can expect continued opposition to the use of AI in many industries, though such opposition will fail, over time, as obvious productivity gains often compel all contestants in a market to adopt the new technologies. 

Study Title	Date	Publisher	Key Findings
The Second Machine Age: Work, Progress, and Prosperity in a Time of Brilliant Technologies	2014	W. W. Norton & Company	The adoption of digital technologies leads to a polarization of the job market, creating high-skill, high-pay jobs while diminishing middle-skill jobs.
The Impact of Digital Technologies on Employment	2016	International Labour Organization (ILO)	Found that automation through digital technologies has the potential to displace a significant number of jobs, especially in manufacturing, but also create new job categories in tech and service sectors.
Automation, Skills, and the Future of Work	2019	McKinsey Global Institute	Predicts that up to 375 million workers may need to switch occupational categories due to the adoption of automation and AI, necessitating retraining and new skill development.
The Future of Jobs Report 2020	2020	World Economic Forum	Identified the net job creation potential from GPTs, predicting that 85 million jobs may be displaced while 97 million new roles could emerge, emphasizing the need for upskilling.
Artificial Intelligence and the Future of Work	2021	Brookings Institution	Discusses how AI adoption can create job growth in sectors requiring complex human interactions and creativity, but also warns of significant job displacement in routine tasks.
The Economic Impact of Artificial Intelligence on Work	2022	MIT Technology Review	Highlights that GPTs like AI can lead to job transformation rather than outright replacement, with new roles in data management, AI oversight, and ethics emerging as key areas of growth.
Industry 4.0 and Its Impact on the Labor Market	2023	Journal of Business Research	Analyzes the impact of Industry 4.0 technologies on job dynamics, indicating a shift towards more specialized roles and increased demand for technical and soft skills.
The Second Machine Age: Work, Progress, and Prosperity in a Time of Brilliant Technologies	2014	W. W. Norton & Company	Examines how advances in automation and artificial intelligence (AI), including GPTs, lead to job displacement in routine tasks, but also creates opportunities for higher-skill jobs in sectors like healthcare and education.
The Impact of Information Technology on Labor Demand: A Review of the Literature	2019	Journal of Economic Surveys	Analyzes the role of IT and GPT adoption in reshaping labor demand across industries, revealing a shift toward higher-level cognitive tasks, while routine manual and clerical jobs decline.
Artificial Intelligence and the Economy	2020	Federal Reserve Bank of Dallas	Highlights that AI and GPTs automate a wide range of tasks, particularly in manufacturing and services, leading to job displacement but also the creation of new roles in data analysis, AI training, and tech support.
Technology, Jobs, and Inequality: A Survey of the Evidence	2018	Economic Policy Institute	Reviews evidence that while GPTs like AI and robotics reduce demand for low-skill jobs, they lead to greater inequality, with job growth concentrated in high-skill and managerial sectors.
Labor Market Polarization and Technological Change: A Historical Perspective	2016	National Bureau of Economic Research (NBER)	Finds that technological advancements, including GPTs, result in labor market polarization: growth in high-skill jobs and decline in middle-skill jobs, with a hollowing out of mid-level occupations.
Automation, Skills, and the Future of Work	2021	Brookings Institution	Concludes that GPT adoption accelerates demand for highly skilled labor (in areas like data science, programming), while jobs in routine sectors such as manufacturing and transportation face displacement.
The Effects of AI and Automation on Jobs and Wages: A Global Perspective	2023	OECD	Examines global trends in AI and automation adoption, indicating that the adoption of GPTs displaces low-wage jobs but creates more skilled positions in technology management, software development, and AI maintenance.
How Automation Affects Occupations: Assessing the Task Content of Occupations	2019	Quarterly Journal of Economics	Analyzes how automation via GPTs impacts occupations by reducing routine, repetitive tasks, but increasing demand for creative, problem-solving, and technical roles.
Digital Transformation and the Future of Jobs	2020	World Economic Forum	Provides evidence that GPTs spur job growth in technology-driven sectors (e.g., software development, cybersecurity) but reduce demand for jobs in routine, manual, and clerical functions.
Technological Change and the Labor Market	2017	Journal of Labor Economics	Identifies that technological progress, including GPTs, leads to increased job turnover and retraining requirements, with displaced workers often finding new roles in technology and service sectors.
Technological Shocks and Labor Markets: Evidence from GPTs and AI	2022	Review of Economics and Statistics	Examines the effect of GPTs on labor markets and finds a clear correlation between GPT adoption and shifts in employment toward knowledge-based industries, with a decline in jobs that involve manual labor.
The Impact of AI and Robotics on Labor Markets: A Review of Empirical Evidence	2018	International Journal of Robotics Research	Reviews empirical evidence on the impacts of AI and robotics (a form of GPTs) on job displacement in manufacturing and logistics, while showing job growth in healthcare, software, and robotics management.