Saving is easier when you have a single goal in mind

"The Fewer the Better: Number of Goals and Savings Behavior," (PDF) a study from University of Toronto's Rotman School of Business on consumer savings strategies, concludes that it's better to have a single thing that you're saving for, rather than multiple savings goals.

Consider two hypothetical individuals, Tom and Jerry, who have both been recently exposed to a
seminar on why it is important to save. While the contents of the seminar attended by both were
identical, there was one notable difference. Tom was told it was important to save because he needed to
focus on several goals – the education of his children, healthcare emergencies and as a stash for a
proverbial rainy day. On the other hand, the seminar that Jerry attended stressed only one goal; say
having enough for children’s education. In linking the case of Tom and Jerry to the research on
mindsets, we believe that when people (like Tom) have several competing goals, they might still be in a
deliberative mindset. That is, they may be contemplating which of these goals should be more important
and by how much, and thus are not readily able to translate the savings goals into action. In particular,
because multiple goals were competing for the limited monetary recourse (e.g., every dollar people save
for their children’s education is a dollar they can’t save for their retirement), thinking about this trade-off
prevents them from moving into an implementation mindset. However, when people (like Jerry) only
have one goal, they no longer need to make goal trade-offs and are more likely to move onto the second
stage of the goal pursuance — a position to think about implementing the goal. As a result, their
commitment with the task at hand (i.e., saving) will be stronger and their savings intention will be
higher.