Run your business not selling on a rising market for your product,  and when it peaks,  you sell as the market declines.  Can you sell fast enough to keep up with the downward price movement?  That is PERS.  The enrolled get the gains over 7.2%,  now,  and the losses,  the actual returns under 7.2%,  are tax payer liability to infill.  If you reduce that to a realistic 6.5%,  it raises the present deficit caused by the over estimation since before the BushObama Recession to more than $50 billion,  essentially doubling the listed liability and that puts into play all sorts of caps,  employer demands,  and huge public budget cuts.  If the return is over 6.5%,  the same old deal with the money not paying for any liability reduction.  
"Now look at what you've got us into,  Ollie!"  Screwed,  blued,  and tattooed.  Hey!  That looks millennial to me.