Framework Definition

Cost of Predictivity

Coined by Richard Ewing, AI Economist

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Definition

The Cost of Predictivity measures the variable cost of AI accuracy. Unlike traditional software with near-zero marginal costs, AI features have significant variable costs that scale with both usage AND accuracy requirements. As AI correctness increases, cost scales exponentially — not linearly. This is the fundamental economic challenge of AI products. Traditional software follows a simple cost model: high fixed development cost, near-zero marginal cost per user. Build the feature once, serve it to millions for pennies. AI products break this model entirely. Every AI query costs compute. Every inference requires GPU cycles. Every improvement in accuracy requires either more sophisticated prompts (more tokens = more cost), retrieval-augmented generation (vector DB queries + embedding generation), or fine-tuned models (massive training costs amortized over queries). The cost structure looks more like a manufacturing business than a software business. The exponential curve is the killer. Moving from 80% accuracy to 90% accuracy might cost 2x. Moving from 90% to 95% might cost 5x. Moving from 95% to 99% often costs 10-20x. This is because the easy cases are solved by the base model, and each additional percentage point of accuracy requires increasingly sophisticated (and expensive) techniques to handle edge cases. This creates what Richard Ewing calls the AI Margin Collapse Point: the usage volume at which AI feature costs exceed the revenue they generate. Many AI features that work beautifully in prototype (low volume, don't need high accuracy) become economically devastating in production (high volume, users demand high accuracy). The AI Unit Economics Benchmark (AUEB) calculator at richardewing.io/tools/aueb helps companies calculate their Cost of Predictivity and identify their specific margin collapse point before it hits their P&L.

Why It Matters

Most AI products fail on economics, not technology. The product works — it just costs more to run than it generates in revenue. The Cost of Predictivity explains why: success makes you poorer unless you understand the exponential relationship between accuracy and cost. For product leaders, the Cost of Predictivity should be calculated BEFORE building AI features, not after launching them. Many teams discover the economics are unworkable only after they've committed to an AI-first architecture. For investors, the Cost of Predictivity is a due diligence essential. "What's your cost per useful AI output, and how does it change as you scale?" separates AI companies with viable economics from those that are quietly burning cash on inference costs. For CFOs, AI costs are often buried in cloud compute bills rather than attributed to specific features. The Cost of Predictivity framework forces feature-level cost attribution — revealing which AI features are profitable and which are margin destroyers.

How to Calculate

  1. 1Total AI compute cost per month (API calls + inference + embedding generation + vector DB)
  2. 2Divided by useful outputs generated (outputs that users actually accepted/used)
  3. 3Equals Cost of Predictivity per useful output
  4. 4Track this metric at different accuracy thresholds to see the exponential curve
  5. 5Calculate your AI Margin Collapse Point: the volume where AI costs exceed feature revenue
  6. 6Use the AUEB calculator at richardewing.io/tools/aueb for automated benchmarking

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Citation

To cite this definition:

Ewing, R. (2026). "Cost of Predictivity." richardewing.io.
https://www.richardewing.io/articles/frameworks/cost-of-predictivity

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Richard Ewing — AI Economist & Capital Auditor