Mark Twain once famously advised buying real estate. “Buy land,” he said. “They’re not making any more.”

Not bad advice, then or now. A look at the most profitable public companies in Los Angeles shows that six of the top 25 are in the real estate business, twice the number of entertainment businesses. The list ranks the local publics on three-year average return on equity, and the results are as clear an indication as any that the market has done well in shaking off the effects of the recession.

Add to those numbers the ever-shrinking vacancy rate in the county’s office market – down to 15 percent in the second quarter, a full point lower than the year earlier – and more than 2 million square feet under construction, and things are looking pretty bright on the real estate front.

Much of that activity is being driven by the tech sector, which continues to expand despite recent concern that investment is slowing down. It’s also interesting to note that the ROE posted by public tech firms landed most of them at the bottom of the list.

The economic realities of the tech sector are a world away from those of the real estate market they help propel. That may go some way toward explaining the big exit that came last week, when Dollar Shave Club took a $1 billion all-cash offer to join the Unilever family. While it is generally seen as a vote of confidence both in the local tech scene and the e-commerce corner of Silicon Beach, one can’t help but note that Dollar Shave opted to be swallowed by a multinational conglomerate rather than take its chances in the public markets.

The list of public companies based in Los Angeles continues to shrink. Perhaps the scrutiny that comes with lists like ours – along with the rigors of answering the analysts, shareholders, and the SEC – makes that inevitable. But as long as the economy is expanding, vacancies are declining, construction is booming, and unicorns are exiting, does the loss of public company headquarters really matter?