Um...will not happen.
Discrepancies between areas are handled contractually by regional and local supplements. Wide disparities already exist in other areas such as paid sick days, extra weeks of vacation, extra paid breaks, and pensions which pay twice as much in some areas rather than others.
For example, your pension out west is potentially worth $600,000 more than the rest of us based on average life expectancy. And you can retire to any location you want so cost of living is not a valid argument in retirement.
You also get paid sick days, and an extra week of paid vacation, some get an additional paid break after a certain amount of hours, and some get double time for excessive OT
If you want even more than the rest of us you will have to gain it by Supplement.