{
  "handle": "ComputationalEntropyRate",
  "gloss": "Bits submitted per bit accepted in a channel that computes, where rejection is meaningful work rather than noise",
  "mechanism": "Treat a channel as computational: it accepts or rejects inputs according to a language (a password validator, an environment selecting viable genomes, a colleague judging an idea). The computational entropy rate is the number of bits that must be submitted for each bit accepted; if 66% of submitted length is accepted, the rate is about 1.5. It looks like the friction of {{channel_capacity}}, but the cause is different: low Shannon capacity reflects meaningless noise, while a high computational entropy rate reflects meaningful rejection, i.e. the channel doing more work. The rate measures the difference in information between two languages, the generator's and the acceptor's. A further ratio, the computational channel flow ratio, compares the average length of accepted inputs with rejected ones: a channel that rejects short inputs early and accepts long ones can consider more options at the same entropy rate, as a writer who bins bad pages early can afford to be more critical.",
  "invariants": [
    "The rate is at least 1; it equals 1 only when every submitted input is accepted",
    "Rejection reflects the acceptor's criteria, not corruption in transit",
    "At the same entropy rate, channels with different flow ratios differ in how efficiently they consider options"
  ],
  "failure_modes": [
    "Reading all friction as inefficiency to be removed, so the options it encodes are lost",
    "Lowering the rate by accepting everything, which removes the channel's useful criteria (e.g. password strength)",
    "Confusing it with noise-limited {{channel_capacity}}"
  ],
  "_meta": {
    "path": [
      "Infrastructure",
      "Primitives"
    ],
    "ring": 2,
    "tier": 2,
    "source": "Adam Timlett, On the Origin of Risk (2025), Ch 16 p.109-116, Ch 17 p.117"
  },
  "sema_id": "sema:ComputationalEntropyRate#mh:SHA-256:4f452b8ec7cb60a7e69fa5509ed17eaa33a77019be8631a7bbb71ae1a24c9144",
  "sema_ref": "ComputationalEntropyRate#4f45",
  "sema_stub": "4f45",
  "dependencies": {
    "references": {
      "channel_capacity": "sema:ChannelCapacity#mh:SHA-256:8693c99893f57b357ed98d0e4b5a56b4a0c8f47eff8efb07763cad8c45c3057c"
    }
  },
  "sema_layer": "Infrastructure",
  "sema_category": "Primitives",
  "used_by": {
    "references": {
      "ConcurrentBetHedge": "sema:ConcurrentBetHedge#mh:SHA-256:9c2a799b9cba80a6358823edeb7cee76593e95596853a6715c1f5bf056b47787",
      "EndogenousStress": "sema:EndogenousStress#mh:SHA-256:5367f1ad026491329822553c265a3e9fefb5555dc7779d8bb5f772ce6af86aa2",
      "FractionalMetaModel": "sema:FractionalMetaModel#mh:SHA-256:b25a96009ba8797d2c4a8673cebfe38ebb0326d237a3669a2a2d7f56aeb5e2c2",
      "ProximateOptions": "sema:ProximateOptions#mh:SHA-256:9b4d9572f268a6bfba63e1edf49f10434b15e7f0fed79e57e815d689317b0ddb"
    }
  }
}