SAN JOSE, Calif. — Silicon Valley's economy has revved up thanks to plucky Internet and alternative-energy startups, according to a new report.

Local technology companies created 33,000 jobs last year — the first increase since 2001, a year after the dot-com downturn. The region's median household income jumped to $76,300 last year, representing a 6.5 percent increase from 2005 and the first uptick since 2001. It decreased 13 percent from 2001 to 2004.

Researchers from Joint Venture: Silicon Valley Network, an alliance of business and community institutions, will discuss the report Friday at the annual "State of the Valley" conference. Former Vice President Al Gore will deliver a keynote speech about green technology.

"We saw the first evidence the downturn was behind us," said Russell Hancock, Joint Venture chief executive. "We've reinvented ourselves."

Researchers define Silicon Valley as a region with 2.4 million people in Santa Clara County and San Mateo County and parts of Alameda and Santa Cruz counties.

The report noted the diversity of Silicon Valley, where English is spoken exclusively in only 52 percent of households. But researchers remained troubled by the valley's racial and ethnic divide. While Chinese and Indian entrepreneurs have excelled, Hispanics, blacks and Southeast Asians have had a tougher time in the tech industry.

Also troubling: High school graduation rates have stalled, juvenile crime has increased, health insurance is out of reach for a growing number of residents, and housing costs force many families out of state.