After three years of sitting at the top of the Forbes priciest American residential real estate list, in December the media company said Atherton had fallen to third place.

Also in December, the website PropertyShark.com said Atherton was number two on its list of most expensive real estate - the same rank PropertyShark had given to Atherton last year.

But local real estate experts say such rankings are mostly good for cocktail party chatter, not long-term planning.

PropertyShark and Forbes compiled their lists in completely different ways. Forbes used median (half higher and half lower) listing prices in the three months ending Nov. 18, while PropertyShark looked at median sales prices for sales closed in 2016. Both looked at ZIP codes, not city limits.

Atherton's median listing price on the Forbes list is $7.16 million.

PropertyShark listed Atherton's median sales price at $5.42 million.

Locally, the PropertyShark top 10 list also included Palo Alto's 94301 ZIP code at No. 8 with a $2.9 million median sales price, Los Altos Hills (94022) at No. 9 at $2.83 million, and Portola Valley at No. 10 at $2.81 million.

The only other local community in the Forbes' top 10 list was Los Altos Hills (94022) at No. 8 with a median asking price of $6 million.

Alain Pinel, a veteran of both the local real estate market and the luxury real estate market, says such rankings "are nice stories to talk about at cocktail parties but are no more relevant than popularity contests."

One problem with such rankings is that they compare small towns with only a few sales to large cities where sales can be in the thousands, he said.

Mr. Pinel, a senior vice president and general manager of Intero Prestigio International who works out of the company's Woodside and Menlo Park offices, said many of the most expensive local sales and listings are not included in such rankings because they never appear on the multiple listing service, and some very high-end sales are not reported until months after completed.

Mr. Pinel said, however, that "it is true that the market as a whole and the high-end market in particular experienced a slowdown last year on the Peninsula." He said the reasons include a lack of inventory much of the year; fewer foreign buyers due to a global slowdown and financial market crashes, especially in China; fewer initial public offerings in Silicon Valley; and uncertainty during an election year that affected top business hubs such as Silicon Valley.

Even so, he said "the high-end market was still quite healthy in 2016," with sales prices in local communities very similar to the previous year.

Tom LeMieux of LeMieux Associates, a Menlo Park resident and real estate broker who also has years of experience, agrees. He said the problem with websites such as PropertyShark and real estate professionals that rely on multiple listing service data "is that (the data) does not tell the full story of the market."

Mr. LeMieux said that in 2015 in Atherton, 31 percent of the total 107 sales were "off market" sales that were transacted through real estate agents but not publicly advertised or on the multiple listing service.

Mr. LeMieux said that, including off-market sales, Atherton median prices were up 6 percent by the end of the third quarter in 2016 over all of 2015. The number of sales declined due to tight inventory levels, he said.

In Menlo Park, where 25 percent of the 392 total sales in 2015 were off-market, prices were down 1 percent in the same time period, Mr. LeMieux said.

"I would say we are in a decelerating market, or a market that is normalizing," he said. Appreciation may be slower than in past years, but prices should not decline, he said, and there should be a balance between buyers and sellers.

The new top-price ZIP code in the Forbes' list is Manalapan, Florida, with a $7.8 million median listing price. No. 2 is the Upper East Side of Manhattan (10075), with a $7.22 median listing price.

The PropertyShark top three are Sagaponack, New York, with a $5.5 million median sales price; Atherton, with a $5.4 median sales price; and New York City's 10013 ZIP code, with a $3.8 million median sales price.

Peninsula cities on the PropertyShark list are:

2-Atherton $5.42 million

8-Palo Alto (94301) $2.93 million

9-Los Altos (94022) $2.83 million

10-Portola Valley $2.81 million

15-Los Altos (94024) $2.63 million

22-Burlingame (94010)$2.23 million

23-Palo Alto (94306) $2.23 million

38-Menlo Park $1.85 million

39-Stanford (94305) $1.81 million

55-Cupertino $1.6 million

58-Sunnyvale $1.56 million

59-Redwood City/Woodside (94062) $1.56

62-Mountain View (94041) $1.53 million

70-San Mateo $1.5 million

73-Mountain View (94040) $1.5 million

75-San Carlos $1.49 million

84-Belmont $1.42 million

Peninsula communities on the Forbes list are:

3-Atherton $7.16 million

8-Los Altos Hills $6 million

16-Hillsborough $5 million

20-Woodside $4.78 million

46-Los Altos $3.6 million

48-Palo Alto (94301) $3.6 million

51-Portola Valley $3.35 million

68-Los Altos $2.9 million

91-Palo Alto (94303)$2.5 million

134-Menlo Park $2.1 million

143-Palo Alto 94306 $2 million

207-Mountain View 94040 $1.7 million

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