'Goods' - Plural Only?

Demand: definition, impact on Canadians' lives and example

Demand for a good or service is also determined by other factors such as consumers’ ... Based on the demand factors listed above, the demand for a good or ...

The interesting thing is that although the dictionaries of economic terms cite "good" as an entry, they refer to "goods" in the plural within the definition. Most other dictionaries do not seem to recognise it as a term with this meaning, and I wonder if it is a reverse effect - "goods" [which is plural] is the accepted term for marketable items, ergo there must be a"good" which is only one of these

goods (used in the plural) a shop specialising in electrical goods. (Note that you do not use good in the singular to mean a single thing of this kind.)

(Times-Chambers Essential English Dictionary)

It's still not clear for me whether the given sentence was correct and whether "goods" or "good" must/may be used for one type of goods .

I looked it up in Longman Dictionary.

It says, 'good' can be a noun but it does not have a meaning of 'something for sale in a shop' so it is definitely not the singular form of 'goods'.

Goods, is a noun but always use it plural form.

Hi Ruslana,

As far as I know, Economists generally talk about 'Goods and Services'.

The given sentence may refer to a specific product.

In the context there is no reference to any specific product. It's just a general article.

Could some more natives express their views, please?

Hi Ruslana

I guess I would put it this way:

The plural form 'goods' is standard (when it means 'wares' or 'things for sale'), and that 'goods and services' is also a standard collocation. However, in combination with the word 'service', the singular is occasionally used in order to indicate that the reference is to a single thing (even though the specific single thing is not mentioned). It also occurs to me that the singular 'good' would probably not be used with the words 'and service' (i.e. no one would say 'good and service') but rather, it would be used in combination with 'or service' -- just as it was in your sentence.