The research team from University of California San Diego and University of Toronto refer to this practice as "parenting by lying."
During the study, they asked U.S. participants in two related studies about parents lying to their children - either for the purpose of promoting appropriate behavior or to make them happy.
Many parents reported they told their young kids that bad things would happen if they didn't go to bed or eat what they were supposed to.
For instance, one mother said she told her child that if he didn't finish all of his food he would get pimples all over his face. Other parents reported inventing magical creatures.
One explained, "We told our daughter that if she wrapped up all her pacifiers like gifts, the 'paci-fairy' would come and give them to children who needed them...I thought it was healthier to get rid of the pacifiers, and it was a way for her to feel proud and special."
"We are surprised by how often parenting by lying takes place," said Kang Lee, professor at the University of Toronto and director of the Institute of Child Study.
"Moreover, our findings showed that even the parents who most strongly promoted the importance of honesty with their children engaged in parenting by lying," Lee added.
Although Gail Heyman, professor of psychology at UC San Diego, thinks that there are occasions when it is appropriate to be less than truthful with a child, like "telling a two-year-old you don't like their drawing is just cruel," she said - she urges parents to think through the issues and consider alternatives before resorting to the expedient lie.
"Children sometimes behave in ways that are disruptive or are likely to harm their long-term interests," said Heyman.
"It is common for parents to try out a range of strategies, including lying, to gain compliance. When parents are juggling the demands of getting through the day, concerns about possible long-term negative consequences to children's beliefs about honesty are not necessarily at the forefront," the expert added.
The research is published in the current edition of The Journal of Moral Education.