jdawdy:erinja,
That would mean only 5,000 to 10,000 fluent speakers, 50,000 to 100,000 intermediate speakers, and 100,000-200,000 Basic speakers. Those numbers seem exceedingly low. While I can agree that the high end of the numbers I posted may not be likely, I think the low-end numbers are at least in the ballpark: 50,000 fluent, 500,000 intermediate-advanced, and 1 million basic

The high end of your low estimates (10,000) seems about right (and remember that few people can remain fluent without language practice, so there's a limit to how long you can be checked out of using the language and still qualify as a speaker). Remember also that many non-fluent people attend Esperanto events and join Facebook groups, so 3000 people at UK does not equal 3000 fluent speakers.

50,000 fluent speakers would imply that if all these speakers are evenly distributed, my home city of Washington, DC should have about 5 fluent speakers, living in the city itself. We actually have probably 3. Remember that this "even distribution" is unrealistic in itself, DC should have more than its fair share, considering that there are large cities in Africa and Asia that probably have no speakers at all. With my numbers, DC would have one fluent speaker assuming even distribution, which sounds about right, since we know that in the real world, speakers aren't evenly distributed and we expect to find more speakers in places where people have the time and money to involve themselves with such things, and internet access to find it.

mbalicki:Tiel aŭ alie, is there any argument against the validity of the estimate based on the Facebook statistics?

I'd think it would depend on whether or not that estimate takes into account the relative penetration of Facebook worldwide. In other words- not everyone uses Facebook, and in some countries there are more popular alternatives than Facebook (which isn't even allowed in China).

Perhaps some of our Chinese users could comment on the number of users in Esperanto-focused social media groups in China.

erinja:50,000 fluent speakers would imply that if all these speakers are evenly distributed, my home city of Washington, DC should have about 5 fluent speakers, living in the city itself. We actually have probably 3. Remember that this "even distribution" is unrealistic in itself, DC should have more than its fair share, considering that there are large cities in Africa and Asia that probably have no speakers at all. With my numbers, DC would have one fluent speaker assuming even distribution, which sounds about right, since we know that in the real world, speakers aren't evenly distributed and we expect to find more speakers in places where people have the time and money to involve themselves with such things, and internet access to find it.

I see what you are saying, but consider this: are you really sure that you only have 3 fluent Esperanto speakers in Washington, DC? The trouble with all this is identifying people- what we really need is to have constructed languages included in the US Census data, for any kind of accurate accounting. You could, quite literally, have 3 fluent Esperanto speakers living within a mile of you, and never know it, unless you are interested in reaching out to them, and they are interested in reaching out to you. For example, I live in an area with a population of about 600,000 (roughly the population of DC) people within a 100 mile radius. Through lernu and E-USA lists I've managed to identify 2-3 advanced (maybe fluent) speakers, 2-3 intermediate speakers, and about half a dozen komencantoj. However, I have to think there are more out there- I'm just not able to get in touch with them: either because they don't join E-USA, or they don't know about the group, or they just aren't very active or interested. This is what I have found is the most difficult part of organizing an Esperanto group- the Esperantists are out there, it's just that finding them is a real challenge.

I think the good estimation is 3 fluent Esperantists per a million. Globally, that will end up to 15-20 thousand people.

The number of truly proficient Esperantists - and by that, I mean native-like - is probably very small. Most speakers still permit a variety of small errors, in both speech and text, and have a vocabulary considerably less developed, especially for terms not easily substituted by compounds (quick, how do you say "eggplant" in Esperanto? Nope, Lernu's en-eo dictionary doesn't have it ).

It doesn't strike me as implausible that there are only 3 "truly" proficient Esperantists in DC (*waves to neighbour Erinja*).

I think if we knew the true number of Esperantists, including a breakdown by proficiency level, we would be quite disappointed.

Tempodivalse:The number of truly proficient Esperantists - and by that, I mean native-like - is probably very small. Most speakers still permit a variety of small errors, in both speech and text, and have a vocabulary considerably less developed, especially for terms not easily substituted by compounds (quick, how do you say "eggplant" in Esperanto? Nope, Lernu's en-eo dictionary doesn't have it ).

It doesn't strike me as implausible that there are only 3 "truly" proficient Esperantists in DC (*waves to neighbour Erinja*).

I think if we knew the true number of Esperantists, including a breakdown by proficiency level, we would be quite disappointed.

I dunno. I don't consider "proficient" (even if "truly" so) to be on the same level as "native-like". the US government language proficiency scale puts speakers at 3 level to be "proficient" but "native-like" doesn't come into play till at least 4+ (on a scale of 0-5)

(and by the way, it's "melongeno".........but I'm a food geek, so......)

"Fluent" is perhaps an unfair standard for an international second language. Haven't you ever had a cab driver who was a recent immigrant from Bangladesh or Haiti, and didn't they speak enough English to get you where you wanted to go, without being fluent in English? Wouldn't it be nice if your car broke down in Finnland and you and the local mechanic both spoke enough Esperanto that you could understand each other, even without being fully fluent? On the other hand, if the UN were to convert to Esperanto as a common language, we'd certainly expect a great deal more fluency from our diplomats.
And while there may be only three good speakers in DC, I've heard that there are five Esperanto clubs in Berlin, so maybe we Americans just need to catch up.

I agree with Erinja. The distribution of Esperantists is very uneven. For instance, Kyrgyzstan, my motherland, has almost 6 million people and 0 fluent Esperanto speakers.
An IT guy should develop an online census to count all Esperantists.

I run the YouTube channel Evildea. I can tell you I don't know the word for "Egg plant" because I've never needed it. Does that make me "not fluent". Well that's hard to say. Also, I would consider 2 million speakers world wide to not be an underestimate. Someone gave DC with 3 native speakers as an estimate. I have worked in the Esp community in Sydney for a long time and I'd say there are 9 active (meeting attending Esperantist), 30 fluent speaking (no interest in meeting / rarely attending meeting Esperantists, and about 40 - 60 in total. I know of 6 who watch my channel regularly but have NO intention of ever attending a meeting. There was a guy (who recently moved to China) who live 10 meters from the usual meetup spot, spoke fluently, and attended once in 4 years (only because he happened to be walking by when it was on. He dropped in for 5 minutes, blew everyone away, then left.

uosuaq:"Fluent" is perhaps an unfair standard for an international second language.

In that case Esperanto has no reason d'etre, as everyone in the world has a rudimentary English knowledge already. Esperanto is intended to facilitate fluent conversations.

DOCENKO_Dmitrij:An IT guy should develop an online census to count all Esperantists.

There are 10400 people in VK Esperanto group, but less than 20 people are posting in Esperanto. There are just sick people who want to be a member of everything. How are you going to prevent them from registering?