San Francisco would be the first mu nicipality in the nation to require employers to ensure that employees who are new parents have fully paid bonding time with their babies under a proposal being crafted by Super visor Scott Wiener.

California pays 55 percent of a parent’s salary for six weeks of bonding time, and Wiener wants to mandate that San Francisco businesses that employ at least 20 people pay the remaining 45 percent. He plans to introduce the legislation at the Jan. 26 Board of Supervisors meeting.

If the proposal becomes law, the extra pay will come too late for Rose Collins. She’s moving to Portland, Ore., next month with her husband and their 4-month-old son, Jack, because the family can no longer make it financially in increasingly pricey San Francisco.

Collins worked as an art director at an advertising firm and planned to return to work after her maternity leave, but quit when the family couldn’t find a two-bedroom apartment with room for their baby for less than $4,000 a month. In Portland, they can buy a house — and she can stay home with Jack longer.

“It would definitely have helped to get that full pay,” Collins, 36, said of Wiener’s proposal as she browsed around Natural Resources, a baby and pregnancy supply store in the Mission District. “San Francisco needs to pursue that for sure — we’re a cutting-edge city.

Moms need support

“We can boast about tech companies that have slides and ball pits,” she continued. “We should be able to boast that we support moms 100 percent.”

When it comes to maternity and paternity leave, the United States has little to boast about. It is the only industrialized country in the world that does not guarantee paid maternity leave. Some states, including California, do give more generous benefits, but they still lag far behind most developed nations.

In California, women who’ve given birth and who have paid into the state disability program usually qualify for six to eight weeks of disability pay, which is paid at the 55 percent rate.

Wiener’s legislation would not apply to those weeks, but would instead apply to the six weeks of bonding time that new mothers can take after their disability ends — and that is also available to other new parents, be they new dads, lesbian partners, gay couples who have babies through surrogacy or adoptive parents. During those weeks, the state pays 55 percent of salary.

Wiener said no new parent should have to make the choice between bonding with their baby or earning a full salary to pay rent and put food on the table.

“There’s been a growing awareness in the United States that our parental leave policies as a country are completely out-of-step with the rest of the world,” he said. “When you do have good, paid parental leave, worker productivity goes up. It’s good for the employer, it’s good for the parents and it’s good for the child.”

San Francisco city employees already enjoy relatively generous parental leave after voters in November approved allowing them to take up to 12 weeks of paid leave without exhausting their sick leave first. Technology companies, too, have been making news by offering more generous parental leave policies. Facebook in November announced it would give four months of paid leave to new parents regardless of gender or country in which they work.

But most leave policies that are more generous than state or federal law tend to benefit only workers on the higher end of the income spectrum, said Jennifer Reisch, legal director for Equal Rights Advocates, a San Francisco group that advocates for equal rights for women in education and employment.

Perk for the privileged

“Very few workers in the private sector actually have access to it,” she said of well-paid leave. “It’s generally only available to the privileged few who are in high-paying professional jobs.”

Julia Parish, a staff attorney with the Legal Aid Society’s Employment Law Center, said the center’s hotline received 1,400 calls from around California last year, including many from San Francisco, and that the majority related to questions about maternity and paternity leave.

Her clients in San Francisco mostly work in nail salons, hotels, restaurants and other parts of the low-paid service sector. She said that while most of the new moms she works with manage to take at least six weeks off after giving birth, many of their husbands don’t even take a day off to bond with their new babies. Passage of Wiener’s bill would mean both parents could stay home for several weeks with their newborns, she said.

“Parents now are forced to choose between really important, fundamental moments in their child’s life and the long-term economic stability of the family,” she said. “It’s truly an impossible choice for any parent.”

Wiener said he knows that in an expensive city, where it’s already tough to run a business because of government mandates and high commercial rents, the proposal could face some opposition. He said he will sit down with business groups to work out any details before submitting the legislation.

Jim Lazarus, senior vice president for public policy at the Chamber of Commerce, said the organization doesn’t have an opinion on the legislation yet and wants more details.

“We look forward to sitting down with Scott,” he said.

Wiener said he plans to structure the legislation so that if California raises its contribution above 55 percent, as has been proposed in Sacramento, local businesses would be on the hook for less money. Also, businesses that currently offer more generous leave policies would be exempt.

Wiener said he considers this just the first step, and he hopes that if San Francisco passes the legislation, it will encourage other municipalities to follow suit.

“San Francisco takes a bold stand, and then other cities and states and then the federal government follow,” he said. “We have so much catching up to do.”

Heather Knight is a San Francisco Chronicle staff writer. E-mail: hknight@sfchronicle.com Twitter: @hknightsf