The reason that you might think that Japanese is more "bloated" is probably because the form of the language you hear most - in TV news and speeches - are in the "polite" form. In that case, they mean to be verbose. But in the casual form, the same thing can be said much shorter.
Also, keep in mind that Japanese has a very different phonetic system. Their phonetic intuition is mostly based on "mora" and many find the notion of syllable confusing and inconsistent. I don't think these two are very comparable (at least mentally).
It's funny that you mentioned that a Japanese newspaper looks more "crowded" than English one. Japanese people would think the exact opposite. The "information density" is really in the eye of the beholder.
The methods this paper employed may certainly be biased in a way that makes Japanese appear less information-dense than other languages.
As for the _written_ language's density, that's entirely different! You say that as written, translations come out to be about the same in Japanese and English, I assume this corresponds to roughly the same number of characters as well? If so, if we can believe the authors of the paper above that Japanese has less information-per-syllable, then perhaps Japanese writing's syllabic/ideographic writing system accounts for this handily such that the information density of _written_ Japanese is about the same as written English.
For what it's worth, I think you were agreeing with me actually:
> Take a look at the front page of a Japanese newspaper and show it to an English speaker, they will think it's "crowded", but I bet if you translated it to English you'd see something that resembles a typical English paper.
What I meant here was that in terms of _written_ information density there are clearly significant gains made thanks to the writing system.
Japanese usually has less characters, but Japanese character are bigger than average latin character.
For example, a random ad on the Yahoo Japan homepage proclaims 予約来場いただくと進呈QUOカード５０００円分, which means "get a 5000 yen gift card if you come visit", but uses literary words like 来場 (arrival/visit) and 進呈 (gift) that would rarely be used in spoken Japanese, and even the polite いただく (to humbly receive) is in the short "dictionary" form instead of being conjugated out the way it would be in speech.
Not op, but I can answer.
Not very common (reported speech, simulating speech, etc.).
You see this in NES/SNES-era game translations. Both versions of the game had to use the same number of characters. So the level of detail in English is quite low compared to the original.
Recently, modders have hacked the English versions of the games to add variable-width fonts to achieve more true translations. Breath of Fire 2 is a good example.
Because each character is equivalent to an entire syllable in English, not a letter.
For example look at the wikipedia article for mother in english vs Japanese
https://ja.wikipedia.org/wiki/%E6%AF%8D%E8%A6%AA
https://en.wikipedia.org/wiki/Mother
In the English sections with pictures there's significantly more white space between the text and pictures than in the Japanese version.
- Why's it so hot today? = 6 syllables
- Nande konna ni atsui no kyou? = 10 syllables (spoken colloquially)
What about written length? You can see the Japanese sentence is a little longer here (when the English uses a non-monospaced font). It's also enough to demonstrates the why using kanji doesn't always provide the huge reduction/compression that you're expecting.
- Why's it so hot today?
- なんでこんなに暑いの今日？
Do you understand than 1 kana represents 1 syllable? They are BY DEFINITION, more concise than Latin letters.
> 1 kana represents 1 syllable
ちゅ <-- 2 kana, 1 syllable
> BY DEFINITION, more concise than Latin letters
smash <-- 1 syllable, 5 latin letters, ~3 kana in length スマッシュ <-- 5 kana
何でこんなに暑いの今日？
Where in the US are you from?
出身は米国の何処ですか?
Japanese sentences are usually shorter than the english translation.
今天怎麼這麼熱？
美國那來的？
This is just wrong as characters are much more concise than using Alphabet because of use of Kanji and the like.
https://ahtaitay.blogspot.com/2020/07/as-native-speakers-we-...
The Japanese language itself has very low "information density" - it takes many more syllables to convey the same thing in Japanese than it does in most languages. This is the result of the language having much tighter phonotactic constraints; literally there are fewer "legal" phonemes (and combinations of them) in Japanese than in most other languages. [1] This isn't a criticism of the language of course - just an interesting tradeoff: A Japanese speaker has fewer sounds to learn, but must learn to speak them faster in order to convey their ideas.
As a result, Japanese speakers are some of the fastest speakers in terms of syllables/second, out of necessity.
Therefore it's no surprise that the typography is going to appear more "densely packed" on a Japanese website. With the exception of Kanji which is a pictographic (logographic? I'm not really a linguist) writing system consisting of many, many characters (and thus can be quite information-dense) - Japanese's other writing systems are purely phonetic - each character representing a single syllable. Take a look at the front page of a Japanese newspaper and show it to an English speaker, they will think it's "crowded", but I bet if you translated it to English you'd see something that resembles a typical English paper.
[1] https://en.wikipedia.org/wiki/Phonotactics