I recently received the annual funding notice of a company pension plan, a large company I worked at for almost twenty years. Among other things, a new federal law allows companies to use more favorable interest rate calculations, thus having a smaller projected funding shortfall and a smaller minimum required contribution to the pension fund.
This is called the Moving Ahead for Progress in the 21st Century Act ("MAP-21"). To me it looks like progress for corporate bottom lines and regress for retirees' pension security.
For example, my former employer would have a funding shortfall under the older law of $1.3 billion. Under the new law the shortfall would be $0.6 billion, less than half. The required minimum contribution would have been $152 million. Now it is $56 million, almost two-thirds less!
On the other hand Congress has really socked it to the Postal Service. Search for
"post office" pensions
One I read was "Background on the $15.9 Billion Loss by the Postal Service". Be sure to read the comments.
The Postal Service was required to significantly increase its reserves in its pension fund. The Postal Service may only put those reserves in government securities, which pay significantly less than the securities corporations may use for their pension fund.
In short, the best Congress money can buy gave its supporters a big break on pension funds and threw stones at its favorite scapegoat.
One of the commenters to "Background" pointed out that the Postal Service is a Constitutionally-mandated organization. I would add that the Constitution doesn't even mention private corporations.