The question is the following: which kind of labour "create" values? If we answer: it is productive labour "creates" value, then this answer is just a tautology. If we answer: it is labour that produces products and that is embodied in them "creates" value, then this answer is still ambiguous because you do not define what is the product. Can we say circulation workers produce "service products"? Are they labour embodied in such so-called "service products", and eventually, are their labour productive? The above answers are not satisfying, these answers still have something needed to be defined. So we need another criterion to judge what kind of labour "create" values. For Masako Watanabe (渡辺雅男. Sorry I just found him in Japanese Wiki, but you can translate this Japanese website page into English by Chrome), a Japanese Marxian economist, to evaluate whether the labour creates value, we need to check whether this kind of lab...
Study on Marxian Economics and real economic world.