A fantastic excerpt for learning the usage of prepositions

Question

German inflation slowed this month, adding to signs that the European Central Bank’s unprecedented stimulus for the euro area has yet to have any significant effect on the currency region’s prices.

Inflation in the bloc’s largest economy, calculated using a harmonized European Union method, slowed to 0.8 percent in July from 1 percent in June, the Federal Statistics Office in Wiesbaden said today. That matched the median estimate of economists surveyed by Bloomberg News. Prices rose 0.3 percent on the month, compared with a median estimate of 0.2 percent.

The ECB announced measures in June ranging from liquidity injections to a negative deposit rate to avert the risk of falling prices and return inflation to policy makers’ goal of just under 2 percent. Data today showed Spanish consumer prices dropped more than economists forecast in the year through July, sliding 0.3 percent compared with a median estimate in a Bloomberg survey for a decline of 0.1 percent.

-- German Inflation Cools as ECB Stimulus Yet to Show Price Effect [Source]

I'm a financial manager seeking the precison of wording in my field, so I'm wondering how the following substitution or addition would change the original meaning:

1. on the month ⇒ for the month

2. of 0.2 percent ⇒ for 0.2 percent

3. sliding 0.3 percent ⇒ sliding by 0.3 percent

4. a median estimate in a Bloomberg survey for a decline of 0.1 percent ⇒ a median estimate by (from) a Bloomberg survey of a decline of 0.1 percent

Answer 1

English prepositions are tough, and you're right to zero in on them as being worthy of a lot of study. They're particularly interesting because they seem almost arbitrary, until you examine them carefully, when they reveal a lot of the subconscious/conceptual-metaphoric thought processes that underlie our language use. Metaphors We Live By is a classic in this field & would probably be instructive, if you have time for a little light reading.

As to your specific questions:

on the month ⇒ for the month

I do not perceive a difference here. "On" appears in this context pretty frequently in the financial press, and might(?) be more precisely referring to an exact monthly period, while "for" just means 'over the course of the month', but I think they're equivalent.

of 0.2 percent ⇒ for 0.2 percent

An estimate of x percent means "in the amount of x percent". "For" would not have that meaning here; "for 0.2 percent" would be used in a context where you were providing an estimate for a 0.2-percent segment of some population or quantity. Something like "It may be bright and sunny, but today will be a terrible day for the 0.2 percent of beach-goers who will be attacked by sharks..."

sliding 0.3 percent ⇒ sliding by 0.3 percent

I don't see a really strong difference here, but I would prefer the first in this context as it sounds more formal, more mathematical. Other speakers might well disagree. If you were speaking of something somewhat less abstract, there would be a difference: "He slid the door 3 inches to the right" is good, "[x]He slid the door by 3 inches to the right" is weird. Note that this is particular to verbs which take a quantity: "[x]He missed his target 3 percent" is weird, but "He missed his target by 3 percent" is fine. (Of course, you could also say "He missed his target of 3 percent", which just means that he had a target, the amount of the target was 3%, but he didn't make that--no information on how much or how little he missed by.)

a median estimate in a Bloomberg survey for a decline of 0.1 percent ⇒ a median estimate by (from) a Bloomberg survey of a decline of 0.1 percent

"in" vs. "by/from" -- "in" identifies the location of the estimate. It may be found in the Bloomberg survey. "By" emphasizes the agency of the source, or stresses who is making the statement. "By" would not be appropriate here, since the survey isn't providing the estimate (it's the analysts who responded to the survey who are the actual agents). "From" could work, but that emphasizes less the location of the estimate than its general origin--a distinction which I am sure sounds vague... I think the difference between "in" and "from" here is that "in" is very precise: this is the source and the location of the estimate, and if you go to the survey, you will see this estimate in it right there on line 12. "From" means that the survey was the estimate's ultimate origin, but it does not precisely locate the estimate as something contained within the survey: rather than a number cited directly from the survey text, there could be an interpretive process to arrive at that estimate, say... I am splitting hairs, a bit; let me just say that "in" in this context sounds more precise and more formal. (Also "in" obviously could only be used for a printed or text source. You can have an estimate "from Bob", but to have an estimate "in Bob" would need surgical intervention!)

"for a decline" vs. "of a decline" -- The distinction I'm seeing here is that if we said "an estimate of a decline of 0.1 percent", that suggests that we're estimating something that has already occurred--we haven't measured it precisely, but we estimate that there was a decline and its magnitude was 0.1 percent. An estimate "for a decline of 0.1 percent" suggests (along with the context) that this is a prediction. We are locating the uncertainty as being about what will happen, rather than the magnitude of what has already occurred.

Though thinking it over carefully, I think the author might have been more precise to say "compared with a median forecast" or "compared with a median prediction", or "expectation," etc.

In conclusion, prepositions are very hard, and there's a lot of variation in the understandings of even native speakers when it comes to these very subtle nuances of meaning.

Answer 2

1) For the month imply a specific month. On the month could mean the month mentioned or each month subsequently.

2) For 0.2 percent would not make sense.

3) You could use either case, but the original case is more concise.

4) this also does not make sense, you would have to re-write the sentence to make your version work.