We say we give to charity to make the world and its inhabitants better off. Unfortunately, our actual giving habits rarely reflect much concern at all for how much good we do. If we were really giving selflessly, we’d care a lot more about effectiveness than our habits indicate.

The Make-A-Wish Foundation—a well-known and very well-financed charity—provides once-in-a-lifetime experiences to people 17 and under living with serious illnesses. By its own account, it costs around $7,200 to fulfill the average request. In contrast, the Against Malaria Foundation—a cause most have never heard of—funds and distributes long lasting insecticidal nets in poor countries with a high prevalence of malaria. According to independent sources, it can save a life for a little under $2,400 on average, a price that likely beats that of any other organization.

Both are doing morally good work, and it’s certainly better to give to either than spend money on a new Rolex. Still, it’s a tragic waste to give to the former instead of the latter. To see why, think about how you’d allocate your money when spending on people you care about. Imagine you have 4 children:

Adam, Bob, Charles, and Dave. Adam has a terminal illness. He will surely die no matter what you do, so you hope to fulfill his lifelong dream of going to Disney World before he passes away. Bob, Charles, and Dave are also deathly ill. Unlike Adam, their diseases are curable, but treatment is expensive and your funds are limited. You simply don’t have enough money to save Bob, Charles, and Dave while providing for Adam’s trip. Here are your options given your cruel financial realities: Deny Adam his wish and save your three remaining children, or send Adam to Disney World and let all four kids die. While the impulse to make Adam’s final days more enjoyable is noble, it is—in comparison to your other children’s lives—a frivolous luxury.

Similar reasoning should apply when it comes to strangers. I’m not claiming that you ought to give as much to charity as you spend on caring for those close to you, but rather you should try to get the most out of your money in both cases. In the above example, terrible (and I hope hypothetical) as it may be, caring about your family’s well being demands judicious allocation of funds. Likewise, if you really care about strangers and their children, even if to a much lesser extent, you’ll try to maximize the good you do with each dollar you give. And until kids that would otherwise die for want of funding, you oughtn’t waste money on providing luxuries to others; rather, you should make every attempt to ensure your philanthropy is directed toward the very best causes.

Of course, it’s not always easy to tell how or what maximizes the good or even what the good is. We should all agree, however, that saving actual lives is far better than making somebody happy for a few days. Nevertheless, Make-A-Wish raised over $180 million in contributions in 2012, while the Against Malaria Foundation received under $3 million that same year.

Compassion demands we start using our heads to guide our hearts when giving. Instead of looking to causes that capture the public’s attention such as Make-A-Wish, or basing philanthropic decisions on extraneous factors like CEO pay and overhead cost, we should be worrying about the bottom line: What charities give you the most moral bang for your buck? And what metrics are best in determining efficacy? If the task of researching charitable organizations sounds daunting, those in the ‘Effective Altruist’ movement, have already done most of the legwork for you. Websites such as The Life You Can Save, Giving What We Can, and the especially in-depth and rigorous GiveWell, consolidate information about the reputation and impact of charitable organizations, report on the transparency of their finances, and rank causes on their overall effectiveness. So despite our wish to entertain the imagination of young children going through hardship, when it comes to charity, it’s the consequences that matter.