Perhaps the largest issue looming for public employee unions in the next few years is the shortfall in government pension systems, which have sunk deeper into the red as the recession has taken its toll. Cities and states around the country — led by Republicans and Democrats alike — have been reducing promised benefits to public workers and retirees as they attempt to cover shortfalls. States need about $1.4 trillion to fulfill their pension obligations, according to the Pew Center on the States.

Over the summer, the Governmental Accounting Standards Board approved new accounting rules for pensions that will make some underfunded plans look worse when the rules begin to go into effect late next year. State and local governments will have to print their total unfunded liability on the front of financial statements.

‘‘It’s going to help identify those plans in serious trouble, which could help policy makers and the public be aware of the need for action,’’ said David Draine, a researcher who tracks pension changes at the Pew Center.