You Don't Set the Price. You Choose the Path.

A cheese plant does not set the price of milk, cheese, butter or whey. The market hands it those prices every morning. What the plant controls is what it does with them: the path. Last week, in Four Jobs, One Set of Rules, we promised this post on what a business controls when it does not control the price.

Same milk, different paths

Follow 100 lb of milk through a cheese plant. Every pound comes out somewhere.

Cheese takes a tenth of the weight. The whey carries the rest, and the few pounds of solids in it each have choices of their own. Those choices are where the margin moves.

More than three dollars on every 100 lb separates the best path from the worst. That can be more than a month's move in the milk price. The price of milk is the market's. Its value in your plant is yours.

Read the paths off the market

Most arguments about price are arguments about forecasts. Often the market has already answered.

Today the cheese curve dips into the winter and climbs back by next autumn. That path is already in the price. Selling next summer's cheese forward takes what the market offers today; it is not a bet on where prices go.

The same reading works for whole paths. Cheese, dry whey, butter, nonfat dry milk and Class III milk all trade as futures. Price each product's yield at its futures price, subtract the milk and the cost to make, and you have the margin the market implies for that path: the crush, as soybean processors call it, or the crack, as refiners do.

Run that for every path and every month, and you can see which paths carry the plant, and how a different futures curve would change that.

Cheese and whey paid most through 2025. Butter and powder have led since March, on a rally in nonfat dry milk, and the futures already price the switch back to cheese and whey next May. Nobody has to forecast it. It is in the prices, months ahead, for anyone who plans milk, staff and storage around it.

Price what has no market

Not every product has a futures contract. It still has two prices that bound it: what its next best use earns, and what the same thing costs to bring in.

Quote the range, not a single number. A wide range marks a thin market where the price depends on who you call. A floor above its ceiling, like lactose here, cannot last; the question is which price moves, and how fast.

One curve, every team

Buying prices at the contract, operations monthly, sales quarterly, risk daily. Each gap between a team's price and the market's is a decision made on an old price.

Put every team on one forward curve, every day, and the weekly meeting moves from whose number is right to what to do at these prices.

Plan for the day that breaks the average

Scenario weights are beliefs. Two committees can hold the same plan and reach opposite answers.

Write the weights down, and test them against the day that matters most. Prices do not move on a bell curve. Most days are calm, and a few are far wilder than a bell curve allows.

Set limits for those days, not for the average one.

The point

None of this needs a view on where prices go. The market sets the price; operations choose the path. We help operators make that choice, and hedge inside limits they set. We do not trade.

The full map of ideas behind this series is in How we think about commerce.

Sources. E. T. Jaynes, Probability Theory: The Logic of Science (Cambridge, 2003). J. Michael Harrison and Stanley R. Pliska, "Martingales and stochastic integrals in the theory of continuous trading" (1981). Bob Coecke, Tobias Fritz and Robert W. Spekkens, "A mathematical theory of resources" (2014). Jean Philippe Bouchaud and Marc Potters, Theory of Financial Risk and Derivative Pricing (Cambridge, 2003).