# Wrong usage of number

In the textbook I read the following sentence: "A monopolist who can fix the price or output (but not both) may want to find out the response of the demand for a product to changes in price."

Are not these two words response and changes misaligned in the number?

According to my understanding of the English sentence structure it either should be responses or change in price.

The reasons why I think they are misaligned is that it creates ambiguity. For example, imagine that monopolist changes price twice. Once it increases by one dollar and another time decreases by 2 dollars. Is monopolist interested in the overall response of the demand (total change in quantity demanded) after the second change in the price or is monopolist interested in the response of the demand for each particular change in the price? Which one do u think is meant by this sentence? Or equivalently to which case is it associated for native English speaker?

• Any response to any changes in price is interesting to the monopolist. I do not see the issue after reading it a couple of times. That I had to read it a couple of times is the actual problem. Apr 24, 2018 at 12:03

No, in this situation "response" would be singular.

If you were to conduct an opinion poll, asking lots of people lots of questions, then you will get lots of responses (one "set of responses" from each person).

However, in this case, you want to quantify how something like demand for a product varies in relation to things you control (e.g. price). This would generally be shown as a curve plotting the observed demand against the controlled price (see Demand Curve on Wikipedia). That curve (singular) is "the response" [of the market] to changes in the price.

Note: it most cases (presumably including the one the original sentence is talking about), it will be changes (plural) in price because you will record demand at several different prices, and therefore there will be several changes in price (e.g. from £1.10 to £1.20; from £1.20 to £1.30 etc.). However, if you were to consider only two prices (e.g. £1.34 and £1.23) then this would be the response (singular) to the change (singular) in price.

Of course, if you can control more than one input, you can measure more than one response of "the market". However, each "response" (singular) would describe how the market behaves across all changes (plural) of the controlled input.

• Would not "change" (singular) be more logical languagewise?
– G.T.
Apr 24, 2018 at 13:27
• Updated answer on why "changes". Apr 24, 2018 at 13:46