I would argue that verses 14 and 15 are more relevant to the context of 'world' in verse 16. "And as...even so..." Moses lifted up the serpent in the wilderness as a means of atonement by faith for the sin of Israel as a nation. However, the serpent was not lifted up as a means of atonement by faith for each and every Israelite. "Much people of Israel died" of the serpent bite before the serpent was lifted up. Therefore, the serpent was lifted up as a means of atonement by faith not to each and every Israelite who was bitten by the serpents, but to Israel as a whole. "Even so..." Jesus is lifted up as an atonement by faith, not to each and every person who ever lived, but to the world in general contrasted with Israel in general. Whereas God loved Israel in general by providing the serpent on the pole, God so (in this manner) loved the world in general by providing His only begotten Son. The emphasis is on 'world' in distinction from Israel, not 'world' in distinction from 'the elect.' I am not even sure John's original audience would have understood the concept of 'election' the way we do since it was Paul who really crystalized that particular doctrine.