Parents might say they love all their children equally, but it's not apparent in their wills

Studies show that parents do indeed play favorites with children in areas such as academic expectations and discipline, despite claiming otherwise.

Now, a new study found that parents are playing favorites during their final acts of life: the distribution of assets in their will.

"We show that unequal bequests are much more common than generally recognized, with one-third of parents with wills planning to divide their estates unequally among their children," wrote Marco Francesconi of the University of Essex, Domenico Tabasso of the University of Geneva, and Robert A. Pollak of Washington University in St. Louis.

Not only do a third of American parents unequally ration out assets to their children, that number has recently increased dramatically.

"The proportion of American parents aged 50 and over who reported having wills, in which their children were treated unequally more than doubled between 1995 and 2010, rising from 16 percent to almost 35 percent," said the researchers.

The main reason for this increase, said the study, is the changing demographics of the American family. Unequal asset allocation is more prevalent in complex families, such as families with stepchildren or with one parent not in the home.

"Stepparents and no-contact parents in complex families may be less motivated than parents in traditional families to provide resources to children with whom they do not share their genes or have not shared their homes," said the researchers.

Using data from the Health and Retirement Study, the researchers found a number of factors that influenced asset allocation to children:

• For parents with stepchildren, the likelihood that all children will even be listed in the will is 28-39% lower than parents with all genetic children.
• In terms of genders, mothers with stepchildren are 38% less likely to include all children in the will, while it is only a 27% drop for stepfathers.
• If a stepchild is more than 10 years younger than the stepparent, the likelihood the stepchild is named in the will increases dramatically.
• If the stepparent is wealthy, there is a much higher likelihood the stepchild is included.
• Stepparents who have long periods of contact with stepchildren are more likely to include them in the will than genetic parents with little or no contact to the child.

To be clear, the study found that the increase in the number of parents creating unequal wills is not just limited complex families, as simple families have also seen an increase since 1995.

The researchers concluded that the shifting demographics of the American family will continue to change the way that wealth is passed down, as more and more complex families develop.

"The implications for intergenerational transfers of these changes in family structure are difficult to predict because complex families created by cohabitation and nonmarital fertility in younger cohorts may behave differently from those created by divorce and remarriage in older cohorts," said the study.

So as families change, so too does the favoritism in wills.