Why do we need to talk about the ethics of giving?
Giving is an absolute good.
Decisions to keep wealth for your selfish little self is clearly less good than giving it away. Isn't it?
Is it ever bad to give?
Well, yes if you are truly impoverished, or if giving food away meant that you could not feed your kids, then yes -- it would be bad to give food away.
Maybe that is a special circumstance, not like the circumstances most of us live in.
Giving is bad if giving creates an unhealthy dependency upon handouts, like American sugar farmers, or other beneficiaries of governments.
If the gift were really a veiled extortion, more like 'Trick or Treat, then giving is not really giving. It is just a bribe or kickback.
Economists talk about the inefficiencies of gift giving because the gift I receive is always an imperfect reflection of what I would have bought for myself. This means some of the gift money is wasted, and to an economist all waste is bad.
It is not especially good to give if I am just expecting an equivalent gift back. That is even in the Bible, Luke 6: 34-36. I'd argue that while it is not actually charitable to do that, but it is still good for the society to trade in this way. It helps build relationships, and society is founded on relationships.
"It is more blessed to give than to receive." Acts 20:35