Wholesale prices soar to 3-year high on energy, food costs Wholesale prices jumped 1.7% in August from July -- their largest gain since June 2009 -- as the cost of food and energy boomed. The seasonally adjusted increase in the producer price index was driven mostly by a 6.4% surge in energy prices, according to the Labor Department. That's the most substantial leap in three years. Gasoline prices swelled 13.6% in August, according to the measure. Another report earlier this week found gasoline prices ticking up nationwide and remaining above $4 a gallon in California. After a summer scorched by drought, food costs rose 0.9% in their third straight month of escalation, marking the largest increase in nine months, according to the government report. Much of the advance is due to dairy prices growing 3%, along with more costly fresh eggs. The overall gauge ticked up 0.3% in July and 0.1% in June. The core index, which strips out the oft-fluctuating energy and food figures, was up 0.2% in August from July. Compared with last year, core prices are up 2.5%. At least customers seem to be in their best mood in years. A study from Chapman University found consumer confidence in California at its highest level since mid-2008. Nationwide fuel prices tick up; California stays over $4 a gallon California consumer confidence at 4-year high, Chapman survey says