Coca-Cola never patented its formula and has protected it for over a century. Patent protection lasts twenty years. What was the calculation?

A. A patent publishes in exchange for a time-limited monopoly

The patent bargain is disclosure for a temporary monopoly, so a secret that can be kept indefinitely is worth more than twenty protected years followed by open competition. The gamble is real, reverse-engineering or independent discovery ends a trade secret with no remedy at all.