Investors own more than half of all the houses in seven California counties.

That’s one eye-catching nugget from my trusty spreadsheet’s review of data on investor activity across the nation from BatchData, a small data tracker that digs deeper into property records than many traditional real estate analysts.

BatchData reviewed California ownership records to identify the state’s owner-occupied residences compared to houses controlled by investors. This study included properties that owners use for short-term or long-term rentals, second homes, and vacation retreats. It does not follow condos, build-to-rent single-family-home projects, or multi-unit properties.

California’s seven investor-dominated counties are lightly populated places, located in remote, northern slices of the state. It’s a good bet that many of these investments are second homes for their owners. These seven counties, best known for recreation and tourism, are …

Sierra: 82% of single-family houses are owned by investors, or 1,308 of 1,588 all houses.

Trinity: 77% – 4,243 of 5,542 houses.

Mono: 74% – 3,200 of 4,305 houses.

Alpine: 68% – 575 of 842 houses.

Plumas: 64% – 7,422 of 11,651 houses.

Modoc: 56% – 1,047 of 1,878 houses.

Calaveras: 54% – 10,385 of 19,209 houses.

That’s a sharp contrast to the statewide total, where investors own 1.45 million houses or just 19% of 7.6 million statewide.

Big county counts

To gain a better understanding of where house investors make their largest bets in California, consider the state’s 20 most populous counties, divided in half by their investor share ranking.

Start with the 10 counties with the highest investor ownership among the big 20 counties. It was topped by San Bernardino, with investors owning 27% of all houses. Then came Tulare (25%), Sonoma (23%), Fresno (22%), Stanislaus, Kern, and Santa Barbara (21%), San Joaquin (20%), Riverside (19%), and Sacramento (17%).

In these counties, primarily locales that are a modest distance from the state’s major job hubs, investors own 21% of the houses – that’s 524,863 of 2.46 million.

Compare that to the other half of the big 20, essentially the state’s urban core. In this grouping, San Mateo County had the largest investor share at 17%, followed by 16% in San Francisco, Santa Clara, Solano, San Diego, Contra Costa, and Orange counties, 15% in Los Angeles and Alameda counties, and 14% in Ventura County.

Combined, investors own 15%, or 624,294, of these 4 million houses.

By the way, in the state’s other 38 counties – including the seven aforementioned investor-dominated ones – investors collectively own 28%, or 301,578 of 1.1 million houses.

Income matters

Note a significant demographic difference between these three groups.

Investors tend to shy away from the big-city counties where the combined annual household incomes run $105,700.

Instead, investors focus on California’s more rural counties, with annual household incomes of $84,700, and the less urban big counties, at $84,400.

Just like house seekers looking for a place to call their own, financial competition may be a deciding factor in where investors choose to go.

Who’s the landlord?

Most of California’s single-family house investors are “mom and pop” types, according to BatchData.

Small-fry owners, with up to five properties nationwide, control 91% of California investment houses.

The rest is divvied up this way: Owners of six to 10 houses control 4% of California investment houses. Investors with 11 to 50 houses own 3% of this Golden State housing group. And 51 or more? Only 2% of investment houses.

Jonathan Lansner is the business columnist for the Southern California News Group. He can be reached at jlansner@scng.com