When liberals see the data on giving, they tend to protest that conservatives look good only because they shower dollars on churches  that a fair amount of that money isn’t helping the poor, but simply constructing lavish spires.

It’s true that religion is the essential reason conservatives give more, and religious liberals are as generous as religious conservatives. Among the stingiest of the stingy are secular conservatives.

According to Google’s figures, if donations to all religious organizations are excluded, liberals give slightly more to charity than conservatives do. But Mr. Brooks says that if measuring by the percentage of income given, conservatives are more generous than liberals even to secular causes.

In any case, if conservative donations often end up building extravagant churches, liberal donations frequently sustain art museums, symphonies, schools and universities that cater to the well-off. (It’s great to support the arts and education, but they’re not the same as charity for the needy. And some research suggests that donations to education actually increase inequality because they go mostly to elite institutions attended by the wealthy.)

Conservatives also appear to be more generous than liberals in nonfinancial ways. People in red states are considerably more likely to volunteer for good causes, and conservatives give blood more often. If liberals and moderates gave blood as often as conservatives, Mr. Brooks said, the American blood supply would increase by 45 percent.

So, you’ve guessed it! This column is a transparent attempt this holiday season to shame liberals into being more charitable. Since I often scold Republicans for being callous in their policies toward the needy, it seems only fair to reproach Democrats for being cheap in their private donations. What I want for Christmas is a healthy competition between left and right to see who actually does more for the neediest.