What is the difference between would rather and prefer?

Question

In the Practical English grammar, A J. Thomson, A.V. Martinet, it is said:

Some statements with prefer+ noun have no exact would rather equivalent: He prefers dogs to cats and He would rather have dogs than cats are not exactly the same.

According to internet sources:construction prefer +noun/-ing+to noun/-ing expresses general preference,while construction with would rather can express both specific and general preference.

So is there actually any difference between these two examples?

He prefers dogs to cats.

He would rather have dogs than cats.

Answer 1

He prefers dogs to cats.

This merely states a personal preference: He likes dogs more than he likes cats. It does not give any hint as to why dogs are his preference. It does not suggest that he has dogs or cats or is even interested in acquiring either of them.

He would rather have dogs than cats.

The meaning here depends on the meaning of "have", which can be subtle:

The following suggest that there is a specific reason for this statement:

(i) he already has dogs and that he had dismissed having cats.

(ii) he is considering possessing some dogs or cats and that, of the two, dogs are, for him, a better choice,

(iii) he has dogs and cats but sees the cats as less pleasing.

(iv) he has dogs and cats and has been told that he must either get rid of the dogs or the cats, and he has chosen to get rid of the cats.

(v) Cats are making a nuisance of themselves in, for example, his garden and he thinks that if he had to make a choice, he would rather have dogs doing the same thing, or

The general preference is

(vi) In a questionnaire, he was asked "If you had to make a choice, which would you have, a dog or a cat?" He replied that he would have a dog.

This is the same as "He prefers dogs to cats."

Answer 2

"He would rather have dogs than cats" is usually referring to what he would prefer to own, though there are other possibilities.

"He prefers dogs to cats" has a wider range of meanings, but is likely to mean that he is more comfortable around dogs than cats. In an appropriate context this sentence may refer to ownership, but it may also refer to which animal he prefers to photograph.