When you loses wallet, it has the effect of removing money out of circulation. Lost bitcoins still remain in the block chain just like any other bitcoins. However, lost bitcoins remain dormant forever because there is no way for anybody to find the private key(s) that would allow them to be spent again. Because of the law of supply and demand, when fewer bitcoins are available, the ones that are left will be in higher demand and increase in value to compensate.
When bitcoin are lost, some business will lost too specially those business that using bitcoin or related to it. If bitcoin lost, some people will affect. A very very negative effect, we all know that people who are veterance here in bitcoin have a lot of experience here and have a big account. So if bitcoin lost, maybe they will dissapointed. And specially like me or those people who starting bitcoin or newbie.