An economist looked at TFP several different ways, and he discovered, to his apparent surprise, that TFP in durable goods has not only increased, but increased significantly. On the other hand, TFP of non-durable goods (food, clothing, gasoline, and similar goods), has stagnated significantly.
Why is the difference important? Because patents are most commonly filed and granted on durable goods, and non-durable goods have significantly fewer patents filed, and in some cases, virtually no patents filed. If patents were a drag on TFP, one would expect durable goods to see the biggest impact because these are patent-intensive industries. Instead, the patent-intensive industries had the greater TFP growth, and the industries least affected by patents has seen TFP stagnate.