Split the Market Out of Your Price

The price that moved and nobody could say why

An outdoor products manufacturer with aggressive growth plans sat down with its rotomolding supplier this spring for a conversation most plants never have. Resin had run up hard, the market was up something like 40 cents a pound from its base, and the supplier's quotes had moved with it. The question on the table was not whether the price should change when resin changes. It was: by exactly how much, measured against what, and who checks the math.

That question has a structural answer, and most supply agreements do not contain it. The price on the PO was one blended number. Inside that number sat two completely different things: the cost of the raw material, which neither party controls, and the cost of converting it, which the supplier controls entirely. Blend them and every market move becomes a negotiation. Split them and the market move becomes arithmetic.

Two components, two behaviors

The structure the sourcing team put on the table is simple. Component one is the resin itself, tied to a named, published index, moving up and down with a 30-day lag so both sides work from finalized numbers rather than estimates. Component two is a fixed adder over resin: additives, processing, freight, margin. That number does not move with the market. It moves when the process moves, a new tool, a different cycle time, a changed spec.

The mechanics matter more than they look. Which index you name is itself a lever: the major published indexes are funded by subscriptions that large producers pay for, and their posted contract prices carry non-market adjustments that can lag reality by years. The lower published numbers tend to reflect where the market is actually transacting long before the headline numbers correct. A buyer who names the wrong index has re-blended the price inside the index itself.

And the lag is a feature, not a compromise. A 30-day lag means May's index sets June's price. Both parties can look up the number. Nobody calls a meeting.

What this does on the floor, not just in the contract

It is tempting to file this under procurement and move on. The floor consequence is the reason to care. When input pricing is a blended negotiation, price changes arrive in lumps, weeks after the market moved, usually attached to a tense phone call. Planning absorbs that: order timing shifts to beat announced increases, inventory builds ahead of negotiations, and the schedule carries buffers that exist only because pricing is unpredictable.

When pricing is indexed, the volatility does not go away, but it becomes legible. Finance can forecast material cost from the same published number the supplier uses. The give-back on the way down is automatic, which is precisely the part that never happens under blended pricing; suppliers pass increases quickly and decreases slowly, not out of malice but because the contract makes every change a discretionary event.

The same manufacturer is now applying the split beyond rotomolding, because the mechanism is not about resin. Any spend category with a dominant, published raw material, film, corrugated, metals, works the same way. The application step is unglamorous: name the index, agree the lag, negotiate the adder once, and put review triggers on the adder tied to process changes rather than market noise.

What a well-run version looks like

The bar here is measurable. Every contract in a resin-heavy category splits material from conversion. The material component names one published index and one lag, and a buyer can reprice the portfolio in under an hour when the index posts. The conversion adder is flat quarter to quarter, and when it moves, there is a process change you can point at. Price conversations with suppliers happen about the adder, roughly once a year, not about the market, every time it moves.

The supplier did not resist the structure. That is the detail worth sitting with: a two-part price protects them on the way up as much as it protects the buyer on the way down. The fight was never between the plant and the supplier. It was between both of them and a blended number neither could see inside.