Bottlenecks
Every barrier to AI diffusion that Narayanan and Kapoor name across eighteen essays: 89 items in nine families, each mapped to the diffusion stock it acts on. Where the tracker has an instrument for a bottleneck, its indicators are linked and carry their current status. Families with no linked indicator are the tracker's blind spots, listed on purpose.
| Family | Acts on | Items | With an instrument | Faster than normal | Consistent or slower | Emerging or unclear |
|---|---|---|---|---|---|---|
| Stage 1: Methods → products (the model-to-product gap) | Products | 17 | 8 | 1 | 3 | 2 |
| Stage 2: Product → individual adoption | Early adoption | 10 | 5 | – | 3 | 2 |
| Stage 3: Organizational and structural adaptation | Adaptation | 15 | 7 | – | 7 | 2 |
| Regulatory, legal, and institutional limits | Adaptation | 13 | 0 | – | – | – |
| External-world and physical speed limits | Adaptation | 8 | 1 | – | – | 2 |
| Safety speed limits (deliberate brakes) | Adaptation | 6 | 1 | – | 1 | 1 |
| Market and economic limits | Adaptation | 8 | 4 | – | 2 | 6 |
| Science-specific bottlenecks | Adaptation | 8 | 0 | – | – | – |
| Upstream: why AI cannot simply accelerate its own diffusion | Return arrow | 4 | 1 | – | – | 2 |
Counts are distinct published indicators linked within the family. “Faster than normal” on a bottleneck's instrument means the barrier is being crossed faster than the normal-technology bands allow; “consistent or slower” means it is holding.
▸Stage 1: Methods → products (the model-to-product gap) · acts on Products
- #1Application development effort does not vanish. The "bitter lesson" applies to methods, not products. Real applications still need hand-built business logic, frontends, integrations, and evaluation. ANT, Slowing, PivotEnterprise pilots with measurable P&L impact consistent with normal
- #2Proof-of-concept to product gap. A demo that works 90% of the time is a capability, not a product. Executives see quick prototypes and miss the 90% of work needed to finish them. Pivot, SWE, SlowingEnterprise pilots with measurable P&L impact consistent with normalDeveloper productivity uplift (METR RCTs) consistent with normal
- #3Capability-reliability gap. Accuracy has risen sharply while reliability has moved only a few points. A model that is right 70% of the time but fails unpredictably cannot remove the human from the loop, and reliability fixes are application-specific. ANT, Slowing, Left, OWE50%/80% horizon ratio consistent with normalMETR 80% time horizon faster than normal
- #4Compounding unreliability in agents. An agent making dozens of LLM calls with even a 2% error rate per step becomes useless end to end. AgentsMatterHuman interventions on 4–8 hour agent tasks (self-reported) emerging50%/80% horizon ratio consistent with normal
- #7Domain-specific product design. General capabilities have to be made useful one domain at a time, which requires deep domain knowledge to find the adoption hurdles (Cursor's code-verification UI is their example). AGIEnterprise pilots with measurable P&L impact consistent with normal
- #8AI companies neglected product engineering. Labs assumed generality exempted them from UX and software engineering, and are rediscovering that both are hard. Slowing
- #9Cost of inference. Cost, not capability, blocks many applications, especially agentic workflows that call models hundreds of times. Cost also sets accuracy, since retries improve success. Scaling, Pivot, AgentsMatter, OWEPrice per unit of capability (cheapest METR-hour on OpenRouter) not yet measurable
- #12Real-world knowledge caps reasoning. AI reasoning in medicine is limited by the medical knowledge that exists, the same limit humans face. Moravec
- #16Benchmarks lack construct validity. Benchmarks overweight what models are good at, miss contextual reasoning, and encourage agents that score well without being useful. Vendor claims cannot be independently checked. Legal, AgentsMatter, GoogleDeveloper productivity uplift (METR RCTs) consistent with normal50%/80% horizon ratio consistent with normal
- #17Real-world messiness cannot be simulated. Whether a system can automate a job is only knowable after diffusion, because no lab environment captures the world's complexity. AGI, OWEDeveloper productivity uplift (METR RCTs) consistent with normal
▸Stage 2: Product → individual adoption · acts on Early adoption
- #18Deployment is not diffusion. Instant availability to hundreds of millions says nothing about how many people use a capability, for how long, or for what. Guide, ANTShare of work hours assisted by generative AI consistent with normalUS firms using AI (Census BTOS) consistent with normal
- #19Low intensity of use. Most users use generative AI infrequently. Nearly a year after release, under 1% of ChatGPT users touched thinking models on a given day. ANT, GuideShare of work hours assisted by generative AI consistent with normalAugmentation vs automation share (Anthropic Economic Index) consistent with normal
- #20Human learning curves. Taking advantage of AI requires continual learning of new workflows and topics. The curve is steep and time-consuming, and it moves at human speed. Guide, Left, AGIShare of work hours assisted by generative AI consistent with normal
- #21Workflow and habit change. The hard part of adoption is users adapting their workflows, which cannot even start in the first months after a launch. ANT, Guide, LegalUS firms using AI (Census BTOS) consistent with normalUS businesses paying for AI (Ramp AI Index) emerging
- #22Most adoption decisions are "no.". Because deployment is instant, people constantly face adoption choices, and the vast majority of the time they decline, for rational and irrational reasons. Guide
- #25Skilled judgment gates "democratization.". Past waves of no-code failed because the barrier is not syntax but the judgment and accountability needed to make good decisions. SWE
▸Stage 3: Organizational and structural adaptation · acts on Adaptation
- #28Organizational change is slower than individual change. For past general-purpose technologies this stage took decades. It has barely begun even in software engineering. ANT, Guide, Left, PivotUS firms using AI (Census BTOS) consistent with normalShare of work hours assisted by generative AI consistent with normal
- #29Drop-in replacement fails. Like electrification, benefits only arrive once work is reorganized: new layouts, processes, hiring, and training. The restructuring is discovered by experimentation, not designed in advance. ANT, LeftEnterprise pilots with measurable P&L impact consistent with normalDeveloper productivity uplift (METR RCTs) consistent with normal
- #34Staged trust. Organizations grant AI access to consequential decisions only after it proves reliable in less critical contexts. ANT
- #35Human-in-the-loop erodes benefits. Requiring approval of every action mostly destroys the value of automation, so it degrades into rubber-stamping or is outcompeted. ANTHuman interventions on 4–8 hour agent tasks (self-reported) emergingDeveloper productivity uplift (METR RCTs) consistent with normal
- #37Underinvestment in complements. Diffusion depends on public goods the private sector underprovides: AI literacy, workforce training, digitization, open data. ANT, AGIUS total factor productivity, private nonfarm business consistent with normal
- #38National diffusion capacity. Following Jeffrey Ding, countries differ enormously in their ability to spread innovations through the economy, and this, not who reaches a milestone first, sets economic outcomes. ANT, AGIUS firms using AI (Census BTOS) consistent with normal
- #40Enterprise resistance to lock-in. Embedded "digital workers" create extreme lock-in and target labor budgets, so enterprises resist, withhold data for training, and demand portability. Stack
- #41Deskilling breaks the talent pipeline. Automating entry-level tasks removes the experiences through which juniors build expertise, a cost that emerges only over time. Legal, SWEEntry-level employment shortfall in AI-exposed occupations emergingRecent-graduate unemployment rate (NY Fed) consistent with normal
- #42Millions of small adaptations. Impact arrives through countless mundane process and policy tweaks, not a single leap. AGI, ANTUS labour productivity, year on year consistent with normal
▸Regulatory, legal, and institutional limits · acts on Adaptation
- #45Professional guardrails. Malpractice liability, professional codes, and device regulation keep doctors from delegating decisions to chatbots. Guide
- #46Regulation that freezes categories. Rules insensitive to experimentation reify business models and organizational forms prematurely, and binary automated/not-automated rules discourage new oversight designs. ANT
- #47Misplaced burdens on model developers. Regulation blind to the developer/deployer split saddles general-purpose model makers with context-specific obligations. ANT
- #48Unauthorized practice of law. UPL rules and their state-by-state vagueness deter new entrants, and bar associations cite model unreliability as grounds for caution. Legal
- #49Law firm ownership rules. Restrictions on who can own or share fees with law firms block outside capital and scaled business models. Legal
- #50Incumbent resistance to reform. Lawyers and commerce groups lobby to narrow regulatory sandboxes despite scant evidence of harm. Legal
- #51Human adjudication time. The speed of human judges, lawyers, and clients caps how fast legal processes can move. Adding judges is politically fraught, and Article III likely requires human judges. Legal
- #52Courts may restrict access. Flooded courts respond by tightening doctrines to keep litigants out or by banning AI, counteracting the gains. Legal
- #53Policy-mandated human steps. Platform policies require developer accounts, 2FA dialogs that block synthetic input, and a human pressing publish. OWE
▸External-world and physical speed limits · acts on Adaptation
- #57Costly, unsimulable errors. Where mistakes are expensive and the world cannot be simulated (driving), safety throttles each iteration of the improvement loop. ANT
- #58AI targets non-bottleneck steps. In an already technological, regulated world, the workflow parts AI improves were optimized by earlier waves. The true bottlenecks resist for external reasons. Guide
- #60Slow external review. Deployment depends on systems the developer does not control. An app took 45 minutes to build and ten days to pass App Store review. OWE
- #61Infrastructure, energy, and compute. Grid capacity constrains training and inference. Token supply is scarce today. Breakthroughs deploy slowly when supporting infrastructure does not exist yet (steam to electric took 40 years). ANT, Stack, Agents26, MoravecCircular financing scale concentratingCloud backlog (remaining performance obligations) concentrating
- #63Unrecognized latent bottlenecks and Amdahl's law. Constraints like RL environments or energy only become visible once they bind, and if many hard steps remain, a hundredfold speedup on the AI-amenable parts yields a small overall gain. Agents26
▸Safety speed limits (deliberate brakes) · acts on Adaptation
- #65Business incentives against unsupervised deployment. Poorly controlled AI is bad business. Unrecoverable failures like deleting production data make companies pull back from hasty automation. ANT, AGI, Left, ScienceHuman interventions on 4–8 hour agent tasks (self-reported) emerging50%/80% horizon ratio consistent with normal
- #66The general-purpose / high-stakes / automated trilemma. For now an agent can be only two of the three, which keeps AI a collaboration technology rather than an automation one. Left
- #67Legibility and control. Removing humans from task boundaries to let AI run end to end reduces oversight, so autonomy is checked by the need to keep systems legible. ANT
▸Market and economic limits · acts on Adaptation
- #71Competitive arms races dissipate gains. In law and science, competition is so intense that productivity gains fuel escalation rather than societal value. Guide, LegalPrice per unit of capability (cheapest METR-hour on OpenRouter) not yet measurableConcentration of business AI spend across labs (Ramp, HHI) unmeasuredSemiconductors' share of stack operating income concentrating
- #73Input-based incentives. Billable hours reward more hours and more output regardless of outcome, absorbing efficiency gains. Legal
- #74Growth is capped by the slowest sector. AI's uneven sectoral effects mean long-run growth is bottlenecked by wherever it diffuses least. AGIUS total factor productivity, private nonfarm business consistent with normalUS labour productivity, year on year consistent with normal
- #75Commodity trap and recoupment. Undifferentiated models push inference to marginal cost, outcomes are hard to measure so value pricing stalls, and incumbents own distribution. This limits how far labs can fund diffusion. Stack
- #76Fixed consumer attention. More apps do not increase usage, capping AI's impact on consumer software. SWE
- #77Publisher distrust. Media organizations' justified wariness and inability to bargain collectively limit the use of journalistic content. ANT
▸Science-specific bottlenecks · acts on Adaptation
- #79Overproduction drowns novel work. Attention is finite. As volume explodes, novel work is lost and AI search concentrates attention on already-famous papers. Science
- #80Publish-or-perish incentives. Institutions reward measurable production, making researchers risk-averse and making AI a tool for chasing metrics. Reform is blocked by inertia and Goodhart's law. Science
- #84Epistemology change exceeds field capacity. Adopting AI requires re-litigating validity per field and model type, which no field can do in a couple of years. SciTool
▸Upstream: why AI cannot simply accelerate its own diffusion · acts on Return arrow
- #89Evaluation does not scale. Every capability increase creates new demand for domain-specific evaluation, which resists automation and absorbs human effort. Left
Essays
- ANTAI as Normal Technology 2025-04-15
- GuideA guide to understanding AI as normal technology 2025-09-09
- AGIAGI is not a milestone 2025-05-01
- LegalAI Won’t Automatically Make Legal Services Cheaper 2026-02-12
- SWEWhy AI hasn’t replaced software engineers, and won’t 2026-06-11
- LeftWhat will be left for us to work on? 2026-07-13
- StackUp the Stack: How AI’s Escape From the Commodity Trap Risks Enterprise Lock-in 2026-07-09
- ScienceCould AI slow science? 2025-07-16
- Agents26AI agents can't yet do open-ended AI research 2026-08-05
- OWEOpen-world evaluations for measuring frontier AI capabilities 2026-04-16
- GovDo AI Risks Require Extraordinary Government Intervention? 2026-05-21
- ScalingAI scaling myths 2024-06-27
- PivotAI companies are pivoting from creating gods to building products. Good. 2024-08-19
- SlowingIs AI progress slowing down? 2024-12-18
- AgentsMatterNew paper: AI agents that matter 2024-07-03
- SciToolScientists should use AI as a tool, not an oracle 2024-06-03
- GoogleDid Google’s AI agents really build an operating system for $916? 2026-05-22
- MoravecFact checking Moravec's paradox 2026-01-29