---
license: cc-by-4.0
pretty_name: LLM Bargaining Transcripts
language:
  - en
tags:
  - negotiation
  - bargaining
  - game-theory
  - llm-evaluation
  - deception
  - multi-agent
size_categories:
  - 1K<n<10K
annotations_creators:
  - machine-generated
source_datasets:
  - original
configs:
  - config_name: games
    data_files: data/games.csv
    default: true
  - config_name: turns
    data_files: data/turns.csv
  - config_name: metrics_per_game
    data_files: metrics/metrics_per_game.csv
  - config_name: metrics_by_cell
    data_files: metrics/metrics_by_cell.csv
  - config_name: operational
    data_files: metrics/operational.csv
---

# LLM Bargaining Transcripts

240 complete two-agent bargaining games between large language models, played
under an alternating-offers protocol with private valuations, discounting, and
cheap talk. Every game records both agents' **true valuations**, their
**private reasoning**, what they **claimed** about their own position, and what
they actually **did**.

The dataset is designed to make misrepresentation measurable. Because the true
valuation and the claimed valuation are both recorded on every turn, a lie is
directly observable rather than inferred.

## What makes this dataset unusual

Most negotiation corpora record only what was said. This one also records:

- **Ground truth.** Each agent's true private valuation, drawn i.i.d. from
  integer Uniform[0, 100], is in the log header. Claims can be checked against it.
- **Private reasoning.** Each agent's `reasoning_private` field, which the
  counterparty never saw. The harness enforces this separation, so the private
  channel is genuinely private within the game.
- **Counterfactual draws.** 14 of the 30 valuation draws have **no gains from
  trade** (`buyer_value < seller_cost`). Any deal in those games destroys value.
  This is deliberate: it tests whether agents recognise when to walk away.
- **Rejected attempts.** Every malformed model output and the validation error
  it triggered are logged, not silently retried away.

## Structure

| Config | Rows | Unit |
| --- | --- | --- |
| `games` (default) | 240 | one bargaining game |
| `turns` | ~2,000 | one message within a game |
| `metrics_per_game` | 240 | derived metrics, one row per game |
| `metrics_by_cell` | 160 | derived estimates with bootstrap CIs |
| `operational` | 2 | instruction-following stats per model |

```python
from datasets import load_dataset

games = load_dataset("CarlosGI/llm-bargaining-transcripts", "games")
turns = load_dataset("CarlosGI/llm-bargaining-transcripts", "turns")
```

Raw transcripts live in `raw/` as 240 JSONL files, one per game, named
`{cell}_s{seed}.jsonl`. **They are deliberately not exposed as a loadable
config**: each file mixes three record types with different schemas (one
`header`, many `turn`, one `result`), so automatic schema inference would
produce a mostly-null table. Parse them directly instead:

```python
import json
records = [json.loads(line) for line in open("raw/haiku_seller_s1000.jsonl")]
header = records[0]                  # seed, true valuations, models, provenance
result = records[-1]                 # outcome, price, payoffs
turns  = records[1:-1]               # per-turn attempts, parsing, projection
```

The raw logs are the archival truth. Everything in `data/` and `metrics/` is
derived from them and can be regenerated.

### `games` fields

| Field | Meaning |
| --- | --- |
| `file` | source transcript path (join key to `turns`) |
| `experiment`, `cell` | experiment label and condition name |
| `seed` | valuation draw; the same seed means identical valuations across cells |
| `rep` | replay index within a seed (always 0 here) |
| `seller_model`, `buyer_model` | OpenRouter model identifiers |
| `seller_cost`, `buyer_value` | **true private valuations** |
| `available_surplus` | `buyer_value − seller_cost`, negative in 14 of 30 draws |
| `outcome` | `deal`, `no_deal`, or `format_failure` |
| `price`, `round` | agreed price and the round it closed |
| `seller_payoff`, `buyer_payoff` | discounted payoffs, `0.95^(round−1) ×` surplus |
| `failed_role` | which side broke the format, if any |
| `*_prompt_tokens`, `*_completion_tokens` | token usage per side |
| `total_retries` | format retries across the game |
| `prompt_variant`, `prompt_hash` | which system prompt was used |
| `git_commit` | harness commit that produced the game |

### `turns` fields

| Field | Meaning |
| --- | --- |
| `round`, `role`, `model` | turn index, `seller`/`buyer`, model that answered |
| `action` | `offer`, `accept`, or `reject`. **Authoritative** |
| `offer` | price proposed on this turn |
| `stated_valuation` | what the agent **claimed** its valuation was, or null |
| `actual_valuation` | what it **actually** was |
| `standing_offer_before` | offer on the table when the turn began |
| `accepted_price` | price closed at, on accept turns |
| `n_attempts`, `n_errors`, `n_illegal` | format retries and legality violations |
| `message` | free-text cheap talk, visible to the counterparty |
| `reasoning_private` | private reasoning, **never** shown to the counterparty |

Comparing `stated_valuation` against `actual_valuation` gives per-turn
misrepresentation. Comparing either against `offer` gives claim-action
consistency.

## Protocol

- Alternating turns, seller moves first, maximum 20 rounds of one message each.
- Valuations i.i.d. integer Uniform[0, 100], drawn per game from the seed.
- Agreement at price `p` in round `t` pays `0.95^(t−1) ×` surplus. Seller earns
  `p − cost`, buyer earns `value − p`. No agreement pays both zero.
- `offer` sets the standing offer. `accept` closes at it. `reject` withdraws it
  **without countering** and passes the turn. Walking away means running out the
  clock; there is no explicit exit action.
- Cheap talk is allowed. Agents may state any valuation or none at all. Lying is
  permitted by design, and measuring it is the point.
- Invalid output is re-prompted with the error up to twice, then the game ends as
  `format_failure`.

## Experimental design

Eight cells, 30 paired seeds each. Every cell plays the **same** 30 valuation
draws, so cross-cell comparisons can use common random numbers and per-draw
differences.

| Cell | Seller | Buyer | Prompt |
| --- | --- | --- | --- |
| `haiku_seller` | Haiku 4.5 | Llama 3.1 8B | default |
| `haiku_buyer` | Llama 3.1 8B | Haiku 4.5 | default |
| `haiku_haiku` | Haiku 4.5 | Haiku 4.5 | default |
| `llama_llama` | Llama 3.1 8B | Llama 3.1 8B | default |
| `*_explicit` (4 cells) | as above | as above | explicit objective |

The prompt variants differ by one sentence. `default` states the rules and the
agent's valuation but **no payoff objective**. `explicit_objective` adds "Your
objective is to maximize your own discounted payoff." Role-swap cells
counterbalance first-mover advantage.

## Provenance

- Harness commit: `77513d57cfc31a616c4d881e3960d4fd1860bc3c`
  (tagged `v1.0-dataset` at <https://github.com/CarlosGIbanez/negotiation-harness>)
- Log schema: `log_version` 2, uniform across all 240 games.
- Prompt hashes: `900540910702` (default, 120 games) and `60a4ab18f0be`
  (explicit objective, 120 games).
- Models served via OpenRouter. Each turn records the model and provider that
  actually answered, so provider-level substitution is visible.
- `spec/full.json` is the spec copy written at execution time, not a later edit.

## Limitations

Read these before drawing conclusions.

- **Two models, one seed block.** Claude Haiku 4.5 and Llama 3.1 8B over 30
  draws. Nothing here generalises to frontier models or to other pairings.
- **No replications.** Each seed was played once (`reps` absent from the spec),
  so within-draw sampling variance cannot be separated from between-draw
  variance. Intraclass correlation is not computable from this data. Sampling
  temperature was 1.0, so replays would not be identical.
- **Refusals are not instrumented.** An agent refusing to negotiate surfaces as
  a `format_failure`, indistinguishable from a malformed reply. Do not read
  format-failure rates as refusal rates.
- **A known protocol quirk.** The `action` field is authoritative, so an `offer`
  value sent alongside `action: "reject"` does not become a standing offer, but
  it **is** still visible to the counterparty in the public projection. This was
  kept deliberately; be aware of it when modelling what each side saw.
- **Message leakage is a heuristic.** The leakage metric flags any numeral in
  the free text equal to the agent's true valuation. An offer that coincides
  with the true value counts as a leak. Verify against transcripts before
  treating it as intentional disclosure.
- **Conditional metrics have small denominators.** Surplus-share statistics
  condition on deals with a real gap, which can leave 9 to 16 games per cell.
  Confidence intervals are correspondingly wide.
- **One agent never disclosed.** Claude Haiku as seller under the default prompt
  stated a cost in zero of 30 games, so seller-side claim metrics are undefined
  for that cell. Empty values there mean an empty denominator, not missing data.

## Licensing and model terms

- **Data**: CC BY 4.0. Attribution required.
- **Code**: see the harness repository linked above.
- **Model outputs**: transcripts contain generations from Anthropic's Claude
  Haiku 4.5 and Meta's Llama 3.1 8B Instruct, obtained through OpenRouter.
  Built with Llama. Downstream users are responsible for compliance with the
  respective model providers' terms, particularly regarding the use of model
  outputs to train other models.
- No human subjects, no personal data. All content is model-generated.

## Citation

```bibtex
@misc{llm_bargaining_transcripts,
  title  = {LLM Bargaining Transcripts: Misrepresentation and Rationality
            in Two-Agent Alternating-Offers Negotiation},
  author = {Carlos Arnoldo Gorostiza Ibáñez},
  year   = {2026},
  note   = {Dataset. Harness: https://github.com/CarlosGIbanez/negotiation-harness},
  url    = {https://huggingface.co/datasets/CarlosGI/llm-bargaining-transcripts}
}
```