Since our founding in 2000, we’ve observed one unshakeable truth to prosperity in the Tri-Counties.

It is this: A vibrant Los Angeles economy is the key to the overall economic health of our region.

When Los Angeles is in a growth mode, everything about doing business in the Tri-Counties gets easier, with the notable exception of traffic.

Tourism flourishes, agribusiness faces increasing regional demand for wines, citrus, berries and other products, construction companies find new opportunities and the spill-over effects are noticeable.

Suffice it to say that it has been quite a while since the greater Los Angeles area was on an upswing. In contrast to San Francisco, which has been in recovery for years, greater Los Angeles has been in a protracted slump.

And it is arguable that Los Angeles’ flagging prospects were not improved under the administration of Mayor Antonio Villaraigosa, who struggled to get the city’s budget under control and who never really embraced the idea of making it easier to do business in LA as a tenet of his administration.

On July 1, Los Angeles inaugurated a new mayor, Eric Garcetti. Like Villaraigosa, Garcetti won in part on the strength of his green credentials and on support from unionized city workers.

But the Los Angeles he is inheriting is a city very much on an upswing — in tourism, in retail and in technology, particularly in the Santa Monica area.

Viaraigosa’s support for downtown revitalization and his support for big infrastructure projects such as the city’s expensive subway to the sea could pay off in the long run. But Garcetti is getting a fresh chance to restart the city’s sometimes contentious relationship with its business community, particularly with small business.

As Los Angeles goes, so goes the rest of the region. And a reset under a new Garcetti administration is a welcome development.