My wife and I file our income taxes as "Married Filing Jointly". There seems to be a drastic difference on our W-2 forms. She has been at her job for 15 years and her W-2 has changed very gradually and without any confusion (i.e. her wages and withholdings have changed predictably), whereas this is my first year full time at my current position. So I am using her W-2 as the "standard" of correctness.
We both claimed 0 allowances. As far as I know, neither of us withheld any additional amount from our paychecks. However, here is the issue. My W-2 Box-1 "Wages, tips, and other compensation" for 2019 was roughly 1.25 times greater than hers. However, my Box 2 "Federal income tax withheld" was only 1.07 times greater than hers (but my "Medicare tax withheld" and "social security tax withheld" were both closer (as 1.19) to our Box-1 ratio (which as stated above was 1.25)).
She did additionally have pension and health benefits deducted from each paycheck. Even then, why wasn't my amount of Federal Withholdings much higher than it was? Shouldn't my withholdings have been higher, bringing us closer to the 1.25 Box-1 ratio on our W-2 forms? (instead of the observed value of 1.07)