The number of active missing persons cases in the U.S. has declined steadily since 1997. This is due in large part to improvements in connectivity and communication, with cell phones and other handheld devices making it considerably easier to track a missing person's potential whereabouts. While this decline is cause for celebration, it is important to note that in the U.S. alone, around 600,000 people are reported missing annually. The great majority of these cases are resolved quickly, often within hours, but a few thousand remain unresolved each year. There are currently over 22,000 open missing persons cases in the U.S., according to the US Department of Justice's National Missing and Unidentified Persons System. Author Claire Jimenez explores the impact the lack of closure resulting from a long-term missing person can have on a family in her novel What Happened to Ruthy Ramirez.

There are several factors that can increase a person's likelihood of going missing. Young people...