Library / Understanding Is Leverage
Chapter 23 — Ackerman Bargaining
Two marketing researchers, Chris Janiszewski and Dan Uy, noticed something odd about how people haggle. They ran experiments, then went and checked five years of actual home sales in a Florida county, and found a pattern that contradicts every instinct to "round it off." Sellers who listed their houses at precise prices — $494,500 rather than a clean $500,000 — ended up selling closer to their asking price than sellers who used round numbers. The buyers, faced with a precise figure, made smaller counteroffers and conceded more ground. In the lab, the effect was the same: people adjust less from a precise anchor than a round one.
Why? A round number reads as a placeholder — "$500,000" sounds like a ballpark someone pulled from the air, practically inviting you to lop off a chunk. A precise number reads as the output of careful calculation — "$494,500" sounds like a figure someone arrived at for reasons, and you find yourself nudging it by hundreds rather than tens of thousands, as if haggling against a documented fact. That single insight — precise numbers are more credible and more immovable than round ones — is one ingredient in the most systematic bargaining recipe in this book, a method developed by a former CIA operative named Mike Ackerman and adopted into the crisis-negotiation toolkit. Most of this book is about transcending crude haggling through relationship and understanding. This chapter is the exception: the disciplined mechanics for when it really does come down to a number.
The Ackerman system
The model is a four-offer sequence built around a single anchor — your target, the price you genuinely want, established by research before you say a word (Chapter 6: anchors must be aggressive but grounded). From that target, you work backward:
The steps, in order:
- Set your target — the number you actually want, grounded in solid research.
- Open at 65% of target. An aggressive anchor that sets the gravitational center low (if you're buying) or high (if you're selling), per Chapter 6.
- Raise in calculated steps to 85%, then 95%, then 100%. Three moves to your real target.
- Between offers, say no with empathy and calibrated questions, not flat refusals. When they push, you don't just resist — you label, you ask "how am I supposed to go higher than that?", you make them work, so each of your increases looks hard-won.
- Make the increments shrink — roughly +20, +10, +5 of your target. This is the subtle engine of the whole system: a pattern of diminishing concessions communicates, beneath the words, that you are approaching your absolute limit. Equal steps invite endless more; shrinking steps say "there's almost nothing left."
- Make your final number precise and non-round — $37,263, not $38,000 — because, as Janiszewski and Uy showed, precise figures resist adjustment. The precision says "this is calculated, this is the real number," and it pins them.
- On the final offer, add a small non-monetary item — a gift, a concession on terms, something outside the money. Reaching past the number when you're "out of money" signals that you're genuinely maxed, and it triggers reciprocity, making the deal feel fair and complete.
Why it works — and where it doesn't
Notice that Ackerman isn't a trick so much as a bundle of the principles this book has built up. The 65% opener is anchoring (Chapter 6). The empathetic no between offers is the holding-the-line skill set (Chapter 16). The shrinking increments are a costly signal — a pattern that's hard to fake and therefore believed. The precise final number is the credibility effect Janiszewski and Uy documented. The closing gift is reciprocity (which we'll meet again in Chapter 24). It's the relationship toolkit and the behavioral science, packaged into a repeatable sequence for the moments when the negotiation really is a contest over a single number.
But know its boundaries, because misapplied it can backfire. Ackerman is built for distributive bargaining — haggling over price, where one party's gain is the other's loss. In integrative situations, where there's value to create by trading across multiple issues (Chapter 3), running a naked Ackerman wastes the opportunity. The 65% opener must still be defensible: an anchor so far outside the plausible range that it reads as insulting or ignorant doesn't anchor, it offends, and can blow up the talk (Chapter 6's caution). And in relationship-heavy or repeated negotiations — with a long-term partner, a colleague, a family member — an obviously gamed four-step sequence can feel manipulative and cost you trust worth more than the spread. Lead everywhere with the relationship and understanding skills; reach for Ackerman when price is genuinely the game, and put it away when it isn't.
That closes the advanced moves drawn from the crisis-negotiation tradition. The remaining chapters of this Part widen the lens beyond Voss entirely — to the broader science of influence, to the great rival school of negotiation, and to the formal theory that underlies all bargaining — so that you can see this whole method in its proper context, and know both its power and its limits.
Try this. For a real upcoming price negotiation, draft your Ackerman ladder on paper: your researched target, then your 65 / 85 / 95 / 100 numbers, with the final one made precise. Write the empathetic "no" you'll use between steps, and pick the small non-money item you'll add at the end. Having the ladder ready is what lets you bargain by design instead of by nerve.
Sources & notes
The precise-number anchoring effect is from Chris Janiszewski and Dan Uy, "Precision of the Anchor Influences the Amount of Adjustment," Psychological Science (2008), including their analysis of five years of Alachua County, Florida home sales showing precisely-priced listings sold closer to asking. The Ackerman bargaining model (target; 65/85/95/100; empathetic calibrated "no"s between offers; decreasing increments; precise final figure; closing non-monetary gift) is attributed to Mike Ackerman and presented in Voss's work (Never Split the Difference, 2016). Anchoring is developed in Chapter 6; reciprocity is taken up in Chapter 24; the distributive-versus-integrative distinction in Chapter 3.