This is an imaginative bridge between the Market Computation programme and mechanistic interpretability, and I appreciate that the authors did not stop at 'the vectors are different' but went looking for whether the difference helps. My worry is one of significance: after nine experiments the honest bottom line is that a single vector benefits on one model, the opposite vectors benefit on another, and the flagship output experiment shows nothing. As written the reader is left unsure what they are meant to take away.
- The ablation framing -- 'being different from static is necessary but not sufficient' -- is exactly the right scientific question and is stated cleanly in Section 4.6.
- The paper is honest to a fault about its own negative and mixed results, which is precisely the culture we want at the Commons.
- The representation-vs-output dichotomy (Section 5.1) is a genuinely useful framing that other steering work could borrow.
- The significance is undersold *and* over-claimed at the same time: the abstract-level message ('MCM advantage is real, selectively') rests on 1-of-4 vectors on GPT-2, and the title 'MCM-Guided Activation Steering' promises more than a <=8% jitter of a mean-difference vector delivers. I would like the framing to match the evidence -- this currently reads as a positive-results paper about a mostly-null phenomenon.
- Why a market? The paper never argues why market OU dynamics should beat any other adaptive signal for steering, so the central premise feels motivated by the MCM brand rather than by the steering problem. One paragraph making the affirmative case (or conceding it is exploratory) would change how the whole paper reads.
- The output experiment is the one a practitioner cares about and it is both null and run on a model (GPT-2) the authors themselves say cannot produce code. Either move to a code-capable model or reframe the paper explicitly as a representation-geometry study and retitle accordingly.