Uncertain Expectations – California’s Long Struggle with How to Measure Defectiveness in a Product’s Design

In the 50-plus years since the inception of the doctrine of strict products liability in tort, a vexing issue for product manufacturers has been how to evaluate and defend against accusations of design defect. Manufacturing defects are relatively easy to evaluate – something either did or did not go wrong on the assembly line, the product either did or did not conform to specifications. But except for the rare and extreme cases where, in hindsight, the design is so clearly misguided that no reasonable engineer would consider it safe, courts, commentators and lawyers have hotly debated the proper benchmark to judge the alleged defectiveness of an entire product line.


Manufacturers like to know what to expect. Without a concrete liability standard, they cannot confidently design their products to satisfy it, and they cannot rationally evaluate their liability exposure when they get sued. Even better for manufacturers would be a standard that actually makes sense, and is reasonably attainable.

Against this backdrop we consider the pitched battle for supremacy between the consumer expectations and risk-benefit tests for adjudicating design defect (CET and RBT, respectively). The two standards are radically different. CET – whether the product performed as safely as the ordinary consumer would expect – focuses on the product’s performance in the specific accident. It essentially solicits the jury’s subjective impression as to whether the design performed as safely as such a product should. Due to its subjectivity, there is no way to reliably predict the result until the jury returns its verdict.

If the primary purpose of tort law is to discourage unreasonable conduct/design decisions, and a rational tort system strongly favors predictability, then one might say that CET is defectively designed.

RBT, on the other hand, is intuitive, sensible and relatively predictable. It asks whether the risk of the chosen design outweighs its benefits. This largely mirrors the objective design process, as it instructs the jury to consider the available design options and weigh their risks and benefits to determine whether the design choice resulted in “excessive preventable danger.” Rather than artificially focus on the design’s performance in the specific accident, it considers the safety and suitability of the alternative and chosen designs across the gamut of uses and potential accident scenarios. With the RBT, if the manufacturer has made reasonable, thoughtful and justifiable design choices among the various options and trade-offs, it should be able to defend its product and avoid liability.

It is easy to see, therefore, why defendants usually prefer RBT, and why the plaintiffs often prefer CET. While most courts have rejected routine application of CET as a stand-alone test, they often include the ordinary consumer’s safety expectations as one of the multiple factors in the jury’s weighing of risks and benefits. And still other courts continue to recognize CET as a viable test, at least in some circumstances.

Where CET remains a stand-alone test of design defect, the remaining frontier is determining when the courts will allow its submission to the jury. If the two standards must coexist, manufacturers deserve to know which test they can expect to confront in a given lawsuit. But in California, that question remains surprisingly, and frustratingly, inscrutable, and predictability remains elusive.

Our humble mission is to sort that out, over multiple posts. First, we provide some historical context. Next, we explore the major case law, drawing some categorical teachings. Then we look for trends in the more recent case law and explore some of the procedural and practical issues presented by operation of CET. Finally, we will track all these issues, and others, on an ongoing basis, as new decisions and developments on the subject emerge and add to, or change, the liability landscape.

First, some brief historical background. CET has its roots in warranty law, where the buyer’s disappointed expectations of the quality and characteristics of the “goods” were a basis for breach of contract/warranty liability in the commercial context. The “expectations orientation” was engrafted into tort law when Justice Roger J. Traynor, seeking to avoid the burdens of negligence law and commercial warranty defenses in Greenman v. Yuba Power Prods., Inc., 59 Cal.2d 57 (1963), rationalized the adoption of strict products liability in tort by drawing on the implied affirmation of quality/safety underlying warranty law. The warranty analogy was incorporated in the Second Restatement of Torts, Section 402A.

After Greenman, the California courts failed to reach any consensus about how to define “defect” or whether they should even do so. The California Supreme Court finally took up the issue in 1978 in Barker v. Lull Eng’g., 20 Cal.3d 413 (1978), and held that CET and RBT were the alternative tests for design defectiveness. Beyond establishing them as the applicable paradigms, however, the court provided little guidance as to their respective spheres of operation, leaving further development to the lower courts.

The lower courts were not able to agree on any workable standards for selecting the appropriate test for the wide variety of design defect cases. Many defaulted to simply allowing the plaintiff to choose the test in each case, with that choice often coming at the close of trial during the charge conference. Finally, the California Supreme Court stepped in 16 years later, in Soule v. General Motors Corp., 8 Cal.4th 548 (1994), to supply the necessary guidance.

Which is where we will pick up the history in our next post on the subject.

How’s that for an opening night cliffhanger?