Price Dispersion

Price dispersion is the spread of prices charged for the same product across different sellers, channels or regions at a single point in time. Economic theory predicts that identical goods should converge toward one price in an efficient market, and online retail persistently fails to do so, which is what makes dispersion worth measuring rather than treating as noise. It is usually expressed as the range between highest and lowest price, or as a standard deviation or coefficient of variation across the matched seller set. Reading it requires reliable matching first, because a spread that looks dramatic often turns out to be a multipack sitting alongside a single unit. Where matching holds, a widening spread points to something structural: a seller clearing stock, a promotion running unevenly across channels, or policy compliance breaking down in one market.

Why it matters

• Signals structural change ahead of the average price moving, since a spread widens before a mean shifts
• Exposes channel conflict, where the same product carries very different prices across a brand's own routes to market
• Locates margin opportunity, because sitting at the bottom of a wide spread usually means giving away price the market was not asking for

How it is used

• Spread monitoring by SKU and category to detect widening or compression over time
• Outlier identification, separating a single aggressive seller from a genuine market shift
• Regional comparison, showing where a product is priced consistently and where it is not

Price dispersion and price discrimination describe different things. Dispersion is variation between sellers for the same product. Discrimination is one seller charging different customers different prices for the same product, which is a separate practice with its own regulatory attention. Dispersion is also distinct from price parity, which asks whether a brand's own channels are aligned rather than measuring how far the whole market is spread.