SACRAMENTO, United States - A new report reveals that living in the US state of California imposes a hefty "cost-of-living penalty" on typical middle-class families compared to the national average costs.

Living in California is already more expensive than in other states, and the higher costs are "unreasonable and completely unnecessary," said the Cost of California Report published by the Transparency Foundation, a California-based organization, on Thursday.

The report calculates the total higher costs paid by Californians in major household budget categories, including housing, utilities, food, gas, transportation, healthcare, insurance, childcare, and taxes.

"In every household budget category, the cost of living in California is exponentially higher than the national average," said Carl DeMaio, the organization's chairman, in a news release.

According to the report, a typical middle-class family earning $130,000 a year would face an extra cost of $26,478 annually by living in California, compared with the national average costs.

Housing cost is the most significant category, the report shows, with homeowners paying 32 percent more and renters paying 47 percent more in California than the rest of the country.

As a result, about 40 percent of Californians are considering moving out of the state. Among them, 67 percent cite the high living costs as the main reason, according to the report.

DeMaio blamed the state politicians' "costly mandates and bad policies" for driving up the living expenses. Incumbent state and local politicians should be "held accountable" for the working families' financial hardships, he said.

The report also makes recommendations on how California's leaders can reduce costs for Californians, such as adopting the same regulations as the lowest cost state in each cost category, creating a state "Cost-of-Living Benchmark" Commission, and proposing a package of reforms for voter approval.