A fascinating parenting book has just been published. It has a jokey cover and is being promoted, somewhat misleadingly, as a humor book because it takes a lighter approach than most other advice tomes.

Still, its point is serious and its topic troubles a whole generation of parents.

The letters, which the authors solicited, ask about a spectrum of problems relating to their 20- and 30-something children:

A son has taken up residence for years in the parents’ vacation home and the parents are asking how to let him know they’d like use of the house back.

A daughter needs start-up money for an online business and parents want to know if they should mortgage their home to provide it.

A mother wants to convince her only son to take a job close to home.

Several parents say their child is depressed, has moved back to their childhood home and want to know what more they can do to help.

The answers take many forms, but they hold the same basic message: Set boundaries and learn to say no.

The subtext is that these parents never developed the ability to do either when their children were younger and, in turn, their children never learned to be self-sufficient and independent. Extrapolated beyond the book covers, it has left a swath of the current population stuck in a co-dependent rut.

According to the latest Census, more than half of adults aged 18 to 24 live with their parents. About 13 percent of those ages 24 to 35 also do, the highest percentage ever recorded by the Census.

Conventional wisdom suggests that the weak economy is to blame for this boomerang generation. But Ende says parenting trends are at least as responsible.

“Parents and adult children need to redefine their relationship as one between autonomous adults. Unfortunately, many modern families do not promote separation; sometimes they actively thwart it,” Ende wrote to me when I asked her what she gleaned from her correspondence with so many parents of adult children.

She’s not the first to make the case. Lori Gottlieb made a similar argument in her popular June Atlantic piece “How to Land Your Kid in Therapy,” written about previously in On Parenting.

Ende tends to be more blunt. Here are excerpts from how she described to me what she sees as a wide-scale problem:

“High school kids these days look independent. They have their own cars, their own phones, their own computers and televisions, their own credit cards. That most, if not all, of their equipment is paid for by their parents seems to be forgotten by both parent and adolescent. Then there is the push to get into college. Parents pay for whatever it takes in SAT tutoring or application-writing tutoring to give their kid a competitive edge. So, the kid arrives at college. No one identifies a problem when Mom and Dad are at registration, when the kid texts Mom about everything, that Mom intercedes with professors about grades, that the kid comes home every other weekend, that he’s got an enormous credit card bill and is paying only the minimum or that he is picking a major without any realistic thought to an after-college work plan.

“If parents are aware of these situations, they may try to remedy them, but they do not see them as red flags. They don’t seem to see that their kid is not on track, that he is not as independent as he seems to be. Sometimes the seriousness of the problem is manifested in college — drugs, severe depression, failing grades — but often the depth of the problem doesn’t become clear until after college. When the child is supposed to be moving into his own life, his own abode, living on his own money, he collapses and moves back home, back to where his development stopped. If a developmental stage is not adequately completed, all others that follow will be compromised and fraught with difficulty. Selecting a mate, marriage, child-rearing, divorce and aging will all be especially bewildering for the unseparated, dependent adult child.

“By now we are all familiar with the terms “helicopter moms,” and “the child-centered family.” Helicopter moms overprotect, overindulge and want their children to be “happy.” In a child-centered family, the child’s needs are always primary. Put those two together and you have a family that avoids frustrating their child and making him “unhappy.” [It’s a family] that doesn’t have a strong parental couple making decisions and [setting] boundaries and limits.

“Additionally, pre-schools and public schools, because of their dwindling funds, have encouraged parents to work in their kids’ classrooms, and organized activities that kids participate in (like Little League) demand enormous parental involvement. Kids are not expected to structure any part of their lives, problem solve, learn from frustration, nor be without their parents….

“Yes, the economy has been a stumbling block for college graduates. They can’t always get jobs in the fields they prepared for. Sometimes though, they didn’t realistically prepare for life after college. Parents and children focused on getting into, then getting through, college, without adequately anticipating the end of the college years.

“I believe that the goal should change from making children happy and protecting them from harm to raising them to be independent adults able to problem-solve and cope in the real and sometimes difficult adult world. A safety net can become a trap. Dependence on one’s parents means lack of real security and often results in low self-esteem, depression and anxiety. Parents should expect their children to take whatever first job they can get and live with roommates so that their adult children can have the adult satisfaction of financial independence and living on their own to begin their own life journey.”

Whew. Those are some harsh accusations.

What do you think? Are you a parent of a boomeranger? Are you providing a safety net? Is it the parents who are responsible for this predicament? Or is Ende misplacing blame?