New laws went into effect in California and Washington state on Sunday requiring employers to post salary ranges on job listings, following similar legislation enacted in Colorado and New York.

Why it matters: New York and California are major employment hubs for big companies, and have outsized influence when it comes to standard-setting for employers. Expect to see this catch on widely in the new year.

• Plus: These laws shift the balance of power in the fraught and mysterious world of pay negotiations — giving job candidates and employees info that's typically closely held.

By the numbers: Companies moved fairly quickly to add pay ranges to job listings in New York City after the law went into effect in November; though some have been slow to adjust.

• As of Dec. 4, 61% of NYC listings on Indeed.com included salary information, up from just 27% a month before the law change, according to the company’s data.

Between the lines: Some companies were afraid to go first, fearing backlash over salary bands that might seem too broad or low, said Kaitlyn Knopp, founder of Pequity, an HR software firm.

• Others are just not doing it; unafraid of the fairly weak enforcement mechanisms for the law.
• Also, updating listings takes time. Human resource and payroll teams are still pretty burned out by the turmoil of the past few years, she said.
• They're also worried that if a recession hits, they'll have to lower the ranges. "That's going to be painful."