IT has been a weird four years for California’s technology sector.

It boomed early in the Covid-19 pandemic as people in the United States and around the world geared up for remote work and directed their spending to online services (such as games, streaming and spin classes) they could consume without leaving home.

But that rise in remote work, combined with highest-in-the-nation real estate costs, strict pandemic rules and other factors, also led to something of an exodus from the state’s coastal cities, with high-profile departures of tech leaders in 2020 and 2021 and even occasional claims that the San Francisco Bay Area’s reign as global tech capital was ending.

A few high-profile departures are still taking place, with Elon Musk announcing this month that he will be moving the headquarters of two more of his companies - X, the former Twitter, and SpaceX - from California to Texas, where he moved Tesla Inc’s headquarters in 2021.

But there have also been stories of tech leaders returning and San Francisco beginning a resurgence, with the boom in generative artificial intelligence - the biggest story in tech now - very much concentrated around the San Francisco Bay.

My fellow Bloomberg Opinion columnist Conor Sen thinks it might even be a good time to buy some slightly marked-down San Francisco real estate.

So are we at the beginning of the end of Silicon Valley and California’s long run as tech epicentre or at the beginning of yet another comeback?

I’ve been addressing this question in various ways for a couple of years now, without coming to a conclusive answer other than that, no, San Francisco isn’t the next Detroit.

Here I’m going to explore it through the lens of tech employment.

What I found is that California has been losing ground to the rest of country in tech jobs since early in the pandemic - with no sign of a turnaround yet. But a long-run view, as well as a quick glance at the venture-capital statistics, gives at least some ground for Golden State optimism.

My numbers are derived from monthly Bureau of Labor Statistics (BLS) payroll employment statistics that allow for a pretty good approximation of tech industry employment in California but not for its individual metropolitan areas - which is why my focus here is on the state rather than the Bay Area/Silicon Valley.

Employment in the six main tech sectors hit an all-time high of 1.01 million in California in July 2022.

Since then, it’s mostly been falling amid broader tech doldrums, with data released last week by the BLS showing an increase of 5,000 jobs in June that might be a harbinger of better times or might just be noise.

In the rest of the US, tech employment grew faster than in California from 2020 to 2022 and has kept rising since, albeit at a slower pace than before. As a result, California’s share of US tech jobs had fallen from 20.7% in May 2020 to 18.1% as of this May (national numbers aren’t available yet for June for a couple of the tech sectors), barely above the post-1990 low of 18% set in 2009.

Given the recent trajectory, it seems inevitable that this share will hit new lows soon.

In the 1990s and 2000s, California’s share of employment in computer-systems design and related services fell while its share of other tech jobs held steady - exactly the healthy-for-California scenario I describe above.

In the 2010s, California’s share of both rose, in my view an unhealthy and unsustainable state of affairs. Now its share of both is falling, which could signal a welcome correction or the beginning of a downward spiral.

It all depends on what happens next. One way to at least guess at that is to look at the venture capital (VC) statistics, on the (admittedly not airtight) theory that jobs follow investment.

The numbers aren’t perfectly compatible but do at least give a rough sense that California’s share of inbound VC investment in the United States, while down from the peaks of the mid-2010s, is still quite respectable by historical standards.

 - Bloomberg