Logos should be redesigned with the passage of time?

Logos should be redesigned with the passage of time? is there any research on the redesign of logo because i have seen many big brands to change the their company's logo and say it has increased our sales. Does this happens?

I think logos shouldn't be redesigned,because they  are the witness of history.

absolutely!.. .when you start your company, logos should be the last to go.. .it represents your company and as soon as time goes by, your clients/customers and future customers/end users will refer to them.. .so don't redesign.. .

When were US Army helmets redesigned to resemble Nazi Germany's? ... since it does seem like the German/newer U.S. version would offer more .... away,

DEFINITELY! However, that's my own personal opinion. take a look at Coca-Cola vs. Pepsi. Pepsi's had their logo changed over 10 times! Meanwhile, Coca-Cola's still the same as when it first started over 100 years ago!

I also agree to you that logos must be changes with the passage of time in order to improve brand image and COMPANY'S promotion.. However, logos must also be changed according to certain requirements of business.

Logos should be created with high talent. it should not be redesigned.

Redesign of a logo is a very delicate and risky thing. Not only do you have to get the new design right, you also need to time it correctly in order to make the best impact possible.