I am 64. I just received my annual Social Security statement and am horrified to see that the predicted benefits that I would receive were I to retire at 64, 66, or 70 have all gone down by about 18%. This makes a huge dent in my plan to retire in two years.
How did this happen? Was there a legislative change that was not well publicized? Is there a new calculation method in use?
There haven't been any legislative changes that would explain the 'reduction' to which you refer, nor has the calculation method changed (https://www.ssa.gov/pubs/EN-05-10070.pdf).
I can only assume that one or both sets of estimates that you received was incorrect for some reason. This could result from various reasons, such as projecting in future earnings that failed to materialize. You may want to use the maximization software available on this website to obtain an accurate benefit estimate. The software can also help you determine your best strategy for claiming Social Security benefits.