The evidence is clear. People are not in the know. When it comes to problem solving, some pet owners do not have adequate knowledge to determine solutions. They are unaware what may be contributing to the problems they face. Many are experiencing the results of unrealistic expectations. The bottom line? Animals, who otherwise might remain happily in their homes are relinquished to shelters across the country.
— Exploring the Surplus Cat and Dog Problem
Their results suggested that education and counseling of pet owners before and after they acquire a pet, and providing temporary housing for pets when owners are experiencing a personal crisis may reduce relinquishment of pets.
— Exploring the Surplus Cat and Dog Problem
Exploring the Surplus Cat and Dog Problem by the National Council on Pet Population Study & Policy summarizes the results of a large research study on why people relinquish their dogs and cats to shelters. This paper is for a general audience, meaning you and me. The academic papers that came out of the same research are also available on their site.