With the rise of social media and "significant organizations" backing the need for reform, a public dialogue on the topic long considered politically untouchable is overdue, said Emmett Carson, CEO and president of the foundation, which manages $2 billion in charitable assets.
"The world changed" with the recession of 2008, and declines in assessed valuations mean public services, including education, are no longer supported in the way people have come to expect, he said.
"It's not working for us anymore. If you talk to county assessors, they'll tell you it's not working anymore."
Gov. Jerry Brown last year declined a challenge from Los Angeles Mayor Antonio Villaraigosa to seek reform of Proposition 13, saying he preferred to focus on restoring the state to financial stability.
Brown seeks a package on this November's ballot that would impose a temporary half-cent sales-tax increase plus an income-tax surcharge on earners of more than $250,000, with proceeds being used to pay down past bills.
The surcharge on high earners would be 1 percent for single filers earning more than $250,000 a year; 1.5 percent on incomes over $300,000 and 2 percent on incomes over $500,000. The sales-tax bump would last four years and the income-tax surcharge five years.
Carson cited an economic analysis in the 2012 "Silicon Valley Index," published Tuesday, Feb. 7, by the public policy group Joint Venture Silicon Valley and Silicon Valley Community Foundation. It tracked indicators like changes in assessed values, value of new construction and assessed value in relation to consumer prices.
It concluded homeowners of similarly valued properties in California pay radically different property tax bills — sometimes quadruple the amount — depending on date of purchase in relation to the 1978 passage of Proposition 13.
A new buyer of a median-priced California home in 2007 pays more than four times the property tax of an owner from 1978, and double the property tax of owners who bought median-priced homes in the 1990s, the report said.
Proposition 13 also has led to a boost in the residential versus commercial share of assessed valuation.
Residential property taxpayers in Santa Clara County, who held 50 percent of the county's assessed valuation in 1977, held more than two-thirds of it by 2007, the report said.
This is because residential properties turn over more frequently than commercial properties and, until the recession, most home sales resulted in large increases in assessed values for single-family properties.
Citing the report, Carson said, "You're going to see a demand for dialogue about what kind of structure will get us a system that's more rational for the environment we face today, and not the environment we faced 30 years ago (when Proposition 13 passed in 1978)."
The report is available online at www.JointVenture.org.
TALK ABOUT IT
Do you think Proposition 13 should be repealed or changed? If so, how? Talk about your ideas on Town Square, the online discussion forum, at www.PaloAltoOnline.com.