Is it possible to explain the informativeness of true identity statements of the form 'a is b' (e.g. 'Hesperus is Phosphorus') while also maintaining that the semantic value of a proper name is exhausted by its referent? An answer to this question seems to depend on, on the one hand, what is understood by "informativeness", "belonging to the form 'a=b", and "semantic value" (or “semantic content” or “semantic contribution”), and on the other, whether it is warranted to presuppose that names can have referents (either because perhaps names are general terms, or because maybe names by themselves do not refer to anything, rather, language users 'use' names to refer to objects/individuals.)
I am a second year PhD student investigating this issue. And at this point in my investigation I have come to be convinced of a negative answer to the question posed above. I think that while the position - that the semantic value of a name is exhausted by its referent - helps explain how we can use language (imagine sound patters, squiggles on paper, or pixel patterns on screen) to describe the world, it does not help explain how language can be used to encode knowledge about the world, particularly knowledge of identifications (e.g. 'Hesperus is Phosphorus'.) Right now, I am trying to clearly explain the notions 'encode' and 'about the world' which I have used here.
On a more positive note, I suspect that to whatever extent the talk of "semantic value" (and more generally, "semantics") is warranted, the very same considerations which give us reasons to accept that the referent of a name is a component of its semantic value (e.g. semantic value is 'invariant') also give us reasons to accept that something more than the referent must also be a component of its semantic value. I am not yet sure of the exact nature of what this 'something more than referent’ could be like. I suspect it could be a description associated with the name which, like the referent of the name, is understood by any semantically competent user of the language.
Before starting my PhD at CEU, I taught philosophy to undergraduate students for a couple of years at St. Stephens College, Delhi. When I am not thinking about the topic of my research, I either discuss other issues within Applied Ethics (e.g. What is Hate Speech? Does love affect the autonomy of the lover and the beloved? If so, how?) with my wife or we spend leisurely time together: cooking food and watching movies.