No, not even remotely. It's a mechanism to reduce public funds and leave more money in people's hands. In accounting terms, a tax deduction doesn't belong in the "expenses" column; it decreases the "revenue" column.
> Thought experiment: if you were setting up a matching program that used public money (i.e. tax income), what would your criteria be? Is that an appropriate use of public funds at all?
Almost never, no. The only case I can think of that would ever be appropriate might be as a means of allowing people to direct spending in a particular area already considered within the purview of government, allowing people to select from a variety of competing services while amplifying their spending power to allow them to afford something considered a necessity. As a means of re-introducing competition to improve quality, it might make sense. (But only after carefully determining that the expenditure in question should actually fall within in the scope of government.)
It provides a major motivation to spend wealth via charities. The extent to which that corresponds to doing good to others is what's in question.
> Thought experiment: what would the charitable landscape look like if charitable donations deducted directly from tax burden, not from taxable income? (Perhaps with some upper limit.)
Even worse, I would think.
The tax break is equivalent to a matching program coming from public funds. Thought experiment: if you were setting up a matching program that used public money (i.e. tax income), what would your criteria be? Is that an appropriate use of public funds at all? I can see that some causes might be good enough to contribute public funds to (though in that case why not spend tax money directly on that issue, rather than via a private foundation?), but any and all organizations that happen to be structured as charities?