Gale is asked to test the purity of Walt’s meth and finds that it’s 99% pure, while he can only produce a version that is 96% pure. From Fring’s standpoint, 96% is good enough, but Gale is impressed that another chemist can achieve a 99% purity level. It is apparent that Gus weighs the costs and benefits of producing 99%- or 96%- pure methamphetamine. After all, the equipment he just purchased is suited for producing both purities, which makes the two varieties substitutes in production. Nevertheless, Gus decides that a purity of 96% will suffice. From his perspective, the cost of working with Walter, who is regarded as unprofessional, outweighs the 3-percentage points increase in the purity of the drug. However, Gus’ methamphetamine, although 96% pure, is inferior to that of Walter and the logic of the Alchain-Allen theorem tells us that he might be losing out as long as it competes with the “blue” drug. In other words, the Alchian-Allen theorem states that, when the same transportation, distribution, tax, or sale-specific markup is added to the prices of two similar varieties of the same product, the relative consumption of the higher quality good will increase. Since from a legal perspective, the risks and costs of distributing methamphetamine are, more or less, the same, regardless of its purity, a relatively larger market share will be accounted by Walter’s “blue” methamphetamine. The scenes within the video clip are also useful for discussing product differentiation as a key characteristic of monopolistically competitive markets. The blue color of Walter’s methamphetamine represents a signal of quality as well as purity that bridges the seller- buyer information gap, a problem that plagues black markets such as those for drugs and other illicit goods or services.

This description comes from Duncan, Muchiri, and Paraschiv (Forthcoming)

See more: Alchian Allen Effect, cross-price elasticity, demand, diminishing returns, elasticity of demand, marginal benefit, marginal cost, monopolistic competition, potency effect, product differentiation, substitutes