A new report from Zillow puts an unsettling number on the growing divide between Silicon Valley’s haves and have-nots.

According to Zillow, the Seattle-based online real estate marketplace, employees of tech giants Google, Facebook, and Apple not only live in homes far above the value of the typical local resident, but their homes are appreciating in value at a far faster rate.

Just yesterday, the Wall Street Journal used some of this data to publish a look at the impact of Apple employees on the local housing market.

According to the latest report from Zillow, the average Apple employee’s home is worth five time as much as the U.S. average. Just five years ago, that gap was only three times as much.

In general, of course, Bay Area housing prices and rental rates are exploding. But even within this real estate gusher, Zillow says tech workers are benefiting at a disproportionate rate.

“This analysis highlights the widening wealth gap between tech company employees and other U.S. workers – a gap that is putting increasing pressure on housing markets where tech companies are booming,” Zillow chief economist Dr. Svenja Gudell said in a statement.

This echoes a point I made yesterday in a story about my mixed feelings regarding the news that Uber was opening a big office in Oakland.

Digging into the numbers a bit, Zillow found, using a mix of housing and census data, that the average Apple employee has a home worth $1.14 million. That’s 27 percent more than the median in San Jose, and 50 percent higher than in the Bay Area.

While the WSJ singled out Apple, it turns out Google and Facebook employees are doing even better. Their median home values are $1.28 million and $1.25 million, respectively.

These gaps are accelerating.

Before 2007, Zillow found that the average Google employee’s home was worth 37 percent more than a typical San Jose home. That gap has grown to 39 percent since then. Facebook and Apple employees have also seen their leads increase.

All of this should be a cautionary tale about bad housing policy and poorly conceived economic development policy. Silicon Valley is enjoying a boom, and other regions want so badly to copy that success.

But, as these numbers indicate, be careful what you wish for.