Who wins, who loses under a wheat tax versus a subsidy?
How does the deadweight loss of the tax compare to the deadweight loss of a price support subsidy?
Why, in social welfare terms, is a tax a better than a subsidy?
To what extent does a price support help achieve our goal of fixing the negative externality?
There may be other reasons, in general, for preferring a tax rather than a subsidy. For instance, what are some general problems we might encounter with a wheat subsidy that we wouldn’t get with a wheat tax?