Ambling innovation: the multi-blade razor

The latest developments in the razor market are interesting. We have gone from twin-blade razors, to triple-blade razors, and now we have the first examples of four-blade razors.

While consumer novelty and pointless innovations are important parts of a functioning economy, I’m worried we are rapidly approaching a dangerous cusp. What happens as we go beyond four blades? Assuming that the size of the blade reservoir –the face of the razor is clearly a function of n (f(n)), where is n the number of parallel blades — stays constant, and is also dual-sized asymptotically decline, then we are governed by the following relationship for the efficacy of the razor:


In short, after a certain point, assuming that the razor face doesn’t grow to the size of a volleyball net, an increasing number of blades will have a deleterious effect on the efficacy of the razor. In the limit, as any solution of the above limit shows, the razor will become all blade.

The implications are very serious, including, possibly, that razors will at some point become effectively single-blade again — albeit one very large blade. Why is no-one talking about this?