Proebsting's Law says compilers double code efficiency every 18 years. I wonder what the doubling interval is for algorithmic performance. I expect it would be tough to calculate, like the cost of living, because algorithmic improvements rarely anymore affect all aspects of code performance. Incremental improvements in sorting efficiency likely have one of the broadest reaches, followed by concurrency improvements and object lifetime analysis. Then there's a long tail of niche applications that only apply to certain domains.