While the CPI at one time was the measure desired by the public, government efforts turned the CPI away from measuring the price changes in a fixed-weight basket of goods and services to a quasi-substitution-based basket of goods, which destroyed the concept of the CPI as a measure of the cost of living of maintaining a constant standard of living.
Perhaps this is an offshoot of the concept that was purportedly invented by the hedge fund community before things went to heck in a hand basket last summer.