Price Discrimination

Price discrimination is charging different prices to different customers for the same or similar product based on willingness to pay, not cost. The goal is to capture more of the consumer surplus — the gap between what customers would pay and what they actually pay — and convert it into producer surplus. When executed well, it raises revenue and can increase total output, moving the market closer to the quantity where marginal cost equals the highest willingness to pay.

First-degree (perfect) discrimination: each customer pays their maximum willingness to pay. No consumer surplus remains. In theory, output expands to the efficient level (where the lowest price equals marginal cost), so total surplus can be higher than under uniform pricing — but the firm captures it all. In practice, first-degree discrimination is rare because the firm rarely knows each buyer's exact reservation price; auctions and personalised pricing get close in some contexts. Auctions and personalised pricing approximate this. Second-degree: the firm offers a menu of options (quantity discounts, tiers) and customers self-select. Different willingness to pay maps to different choices. Third-degree: the firm segments by observable group (age, geography, time) and sets a price per segment. Student discounts, regional pricing, and peak/off-peak rates are examples. All require some market power and the ability to prevent arbitrage — resale must be costly or impossible.

The strategic implication: if you have market power and heterogeneous customers, uniform pricing leaves money on the table. The discipline is identifying segments with different elasticities or willingness to pay, designing a price structure that captures it, and preventing leakage (arbitrage) between segments. The same logic applies to B2B (enterprise vs SMB, by industry) and consumer (tiers, coupons, dynamic pricing).

Not all price variation is discrimination. Different prices for different products (e.g. premium vs standard) may reflect cost or value differences. Discrimination in the strict sense is when the same or similar product is priced differently by buyer or segment, and the difference is not justified by cost. In practice, product and price are often designed together — tiers bundle different features with different prices — so the line between "different product" and "same product, different price" is strategic. The goal is the same: capture more surplus by aligning price with willingness to pay.

Welfare effects are ambiguous. First-degree discrimination can increase total output (and total surplus) compared with uniform pricing, but it transfers all surplus to the firm. Third-degree discrimination can either increase or decrease total welfare depending on demand shapes; it often allows the firm to serve a low-WTP segment that would not be served at a single price, which can be efficiency-enhancing. The normative case for or against discrimination is therefore context-dependent. For the firm, the positive case is clear: discrimination raises profit when segments differ and arbitrage can be prevented.