This is hopefully a fun question that is a little bit off the standard path. It's meant to elicit a light conversation but nevertheless one that illuminates fundamental characteristics of Chinese as a written language.
Question: Twitter, which was designed with English speaking users in mind, has a limit of 140 characters per tweet, to enforce a certain brevity and effectively encourage the development of a continuous stream of new content. One advantage of Chinese is that, in Twitter, you can convey a LOT more information in 140 characters than you can in English! But just how much more? My question, and again of course this is purely in the realm of hypothetical, is: How many characters would Twitter have allow if it wanted to let English-language users convey as much information as Chinese speaking users now enjoy?
To go back to my earlier thread about the Hong Kong subway's warning about not standing in the way of a train's closing doors, in Chinese (Cantonese), it is: "請勿靠近車門" and in English is: "Please stand back from the doors." Almost magically, the two spoken languages, independently developed over the course of centuries on opposite sides of the planet, share precisely the same level of economy: Each announcement is just six syllables long. But there is a big disparity in the economy of the written languages. English consumes 27 written characters (and five spaces) to convey what Chinese says with just six characters.
So to extend this one random example into the world of Twitter character limits, where spaces between words do count against your limit, that's roughly five times more characters in English than in Chinese. Therefore, Twitter would have to raise its character limit to 700 characters for English language tweets to match a 140 character limit on Chinese language tweets. Or, looked at another way, Twitter would have to reduce the limit on Chinese language tweets to 28 characters to match the existing 140 character limit on English language tweets. Obviously this is not scientific or even remotely rigorous. Perhaps studies have been done on this question.
As a final disclaimer, I hope it is clear from this question that I am making NO normative judgment about whether one writing system is in some way "better" than another. All written languages have their inherent beauty, and all should be celebrated for that. I'm shedding those thoughts here for a focus purely on the mathematics of information-conveyed-per-character, and nothing more. Also, I'm not suggesting that Twitter ever would, should, or even could have separate limits for separate tweets based on the type of language being used, especially since any one tweet can draw from multiple languages. The thing about Twitter is just meant to serve as a proxy for the underlying question of how many characters Chinese generally uses in comparison to English.