textile donations in particular devastate indigenous clothing industries. So while sending a dress (or a few million t shirts with the superbowl logo of the team that wound up losing, or TOMS shoes) might feel good, in the long run it's actually harming the local economy and erasing local culture as expressed through clothes.
There's actually a term for this sort of well-meaning but harmful donation: SWEDOW. It stands for "stuff we don't want."
http://www.foreignpolicy.com/articles/2011/10/11/haiti_...