The juxtaposition of these two statements never fails to make me boggle a bit. You think my hair is pretty, so you think I should cut it? Ok, ok…I know that’s not what they mean, but how is that any different than me walking up to a person and telling them, “That’s a really pretty dress! You should donate it to Goodwill!”
Either way, it’s kind of rude to suggest to someone the means by which they allocate their personal resources toward charitable donations. Just because you’ve got rooms full of furniture that you only use when your in-laws come to visit doesn’t mean that I’m going to come over to your house and tell you that you should donate it to Furniture Bank because they give furniture to people who need it more. However, if you have furniture you’re actually looking to get rid of, that may be an option for you, as might your local Freecycle if you’re not looking to go the charity route. I’m happy as long as long as you’re not putting perfectly good consumer goods in a landfill.
Anyway, I digress. When I get the inevitable Locks of Love comment, I have to beat back all of the snarky comments I’m tempted to make and politely reply, “I don’t plan on cutting my hair any time soon, but when I do, I won’t be donating to Locks of Love.”
This usually prompts responses of, “But they help kids with cancer. Don’t you want to help kids with cancer?” Or something along those lines. This gives me an opportunity to educate, and while I enjoy bursting people’s self-righteous bubbles as much as the next guy, I hate bursting the bubble of someone who has actually donated and honestly thought they were doing good and just wanted to spread the good around. But it has to be done.
Facts & Assumptions
First comes the gentle correction of fact. Locks of Love does not provide hair pieces to kids with cancer. They “[provide] hairpieces to financially disadvantaged children under age 21 suffering from long-term medical hair loss from any diagnosis,”  which usually excludes hair loss from cancer treatment, since the hair loss is temporary. Locks of Love primarily works with kids with alopecia areata, an autoimmune disorder that causes follicle death. 
So that’s the good news. If you donate to Locks of Love, you might still be helping a child, but it’s not necessarily the child that you thought.
Next comes the slightly less gentle correction of assumption. Locks of Love does not give most of its hair pieces away. It may give a few of them away, but most of them are provided to children with permanent hair loss at a reduced cost based on a sliding scale of financial need. 
So ok, we’ve established with information from the Locks of Love website that if you donate or have donated your hair, it might go to provide a hair piece for a kid with alopecia at a reduced cost. Still not so bad. But I keep using that word, “might.” And that’s where the bubble usually gets burst.
Why your hair (and mine) probably won’t make the cut
In order for hair to be made into a high-quality wig or prosthesis, it must be a minimum length (Locks of Love asks for 10 inches or longer) and have minimal damage. While the Locks of Love website states that it will accept hair that has been colored (but not bleached) or permed, most hair that has been processed in any way is too damaged to make prosthetic hair pieces such as the ones that Locks of Love provides. This, combined with misunderstandings about what can and cannot be donated, results in as much as 80 percent of all donated hair being rejected for prosthesis manufacturing. Of that 80 percent, some of it thrown away–mostly donations that are moldy because they are sent wet, donations that are too short and donations that are too damaged for any sort of hair piece manufacture. 
The rest is still technically acceptable for manufacturing hair pieces, but Locks of Love receives far more donations than it does requests for hair pieces, allowing it to choose only the very best donated hair for its prostheses. Odds are, your hair (and mine) won’t make the cut. Gray hair, for obvious reasons, cannot be used for children’s hair pieces, but is still acceptable for wig making. So is much of the hair that Locks of Love doesn’t send to its manufacturer, Taylormade Hair Replacement. But that hair never makes it into a prosthesis for a child with permanent hair loss. 
Finances, economics and where the hair goes
In 2002, Locks of Love received enough donated hair to make 10,000 hair pieces. (At 10 ponytails per hair piece, that adds up to at least 100,000 donations that, in theory, were acceptable for wig making.) In that same year, the charity provided only 174 hair pieces. The majority of the remaining 98,000+ ponytails that are not used each year are sold, on average, to a tune of just over $3 per ponytail.   This is somewhat less than the estimated fair market price of $5-10 per ounce (minimum) for wig-quality hair. Some ponytails can fetch $500 or more on the open market. 
To be fair, other hair donation charities such as Wigs 4 Kids and Great Lengths also sell excess hair (though I don’t have figures for these charities). The proceeds from the sales typically go toward operating costs, and in the case of Locks of Love, the excess is donated to alopecia research.  To me, however, my hair is worth much more than the $3 that it will likely be sold for. The market probably values it more, as well. If I were to sell my hair and donate the proceeds, it would likely do more good than donating the hair itself. To that end, I then could use the value of my hair to further any cause under the sun, from disease research to animal welfare to humanitarian aid.
The sale of hair by Locks of Love (and perhaps also other hair charities) has another unintended effect–it tends to depress the overall market price for human hair. When a market is flooded with a good at a price below the current market price, this tends to force the overall price downward. This effect is particularly harmful to women in the poorest areas of developing countries who rely on the sale of their hair to bring money into their communities or provide for their families. The majority of commercially-used human hair comes from South Asia, where the economies of some small, rural villages are buoyed by the income from the sale of human hair. This effect is also seen in some poor areas of Eastern Europe.
In short, the donation of your hair may do more harm than good.
Why pick on Locks of Love?
Locks of Love is by far the largest and most visible of hair donation charities. They have also been the least forthcoming about their practices. They’ve improved in recent years, but compared to the number of donations and amount of publicity they receive, their impact is small and their mission is probably the most misunderstood and the most misappropriated of all hair donation charities. Also, because of the large number of donations they receive, the likelihood that your donation will go to the cause you think it is, is very small.
If you really believe in the missions of the various hair charities, more good would likely be done if you just sent them a check. They would then be able to use more of the hair that they do receive (and trust me, they will continue to receive plenty of hair regardless of what anyone says about them), they’d have to sell less of it (thereby helping to preserve the price of human hair on the open market), and your donation will likely have more of a direct effect on the manufacture of a prosthetic hairpiece.
As I mentioned before, it is possible to sell your hair. Some wig makers will buy your hair from you directly. Ebay also allows the sale of human hair, and there are many websites dedicated to the auction and sale of human hair. As a warning, some of these sites are more reputable than others. Some cater to a clientèle with more a prurient interest in your hair, and you might want to avoid them if that makes you uncomfortable in any way. I’ve never actually sold my hair, so I can’t provide any advice other than “there are websites out there.” Do your research and trust your own judgment.
If you’re attached to the idea of doing good with your hair, you can donate the proceeds from the sale. This definitely gives you more flexibility as to the kind of good you can do. If you’re attached to the idea of donating your hair specifically, you may want to look into Matter of Trust, an organization that accepts hair of all lengths and conditions that they weave into mats to help clean up oil spills. This means that they can even use the few inches from your trim or the hair you just chopped off due to that unfortunate incident where you tried to bleach your hair for the summer and accidentally fried it instead. They even accept animal hair, so if you have a long-haired cat or dog in need of a summer grooming, they can get in on the action, too. Given the current oil disaster in the Gulf of Mexico, this organization is in particular need of donations right now.
Of course, you also have the option of just keeping your hair and donating your time. Given a choice, I’d pick this one over donating my hair or my money (not that I have much of the latter) every time.
 Locks of Love. “Mission and Vision.” http://www.locksoflove.org/mission.html
 Locks of Love. “Our Prostheses.” http://www.locksoflove.org/prostheses.html
 Hayt, Elizabeth. (September 6, 2007) “Lather, Rinse, Donate.” The New York Times. http://www.nytimes.com/2007/09/06/fashion/06locks.html?pagewanted=print
 Flipflopjou. “Locks of Love.” http://www.squidoo.com/locksoflove
 MSNBC. (April 12, 2004) “Sell Yourself for Cash.” http://www.msnbc.msn.com/id/3949869/