A general contractor who lives in my neighborhood has done several projects for us over the last decade. He has been honest, reliable and competitively priced, and he has delivered quality work. Recently, he started our kitchen renovation, and it is as if we are working with a different person. He has made numerous mistakes, which have required fixes. He occasionally smells of alcohol and admits that he has “a beer” at lunch. Although he is on the job every day, he has not fulfilled the oversight component that we expect from a general contractor, and we have gradually taken over managing the project. Eventually, we received enough confirmation that his work is substandard from subcontractors and advisers that we found an alternate means of completing the project.

Because he lives in my neighborhood and we know his family, we are aware that they have suffered a challenging personal tragedy in the last few years, which may have impacted his mental health and drinking patterns. We respect him and are concerned. We are also confident that no serious damage has been done to our project and that he will make us whole for any losses we have suffered.

My community is active on Nextdoor, and I have often referred neighbors to him. If I were to post a negative review, it could significantly impact his business. (He has already lost any future referrals from me.) Am I obligated to alert my neighbors that he is no longer reliable? Name Withheld

It’s understandable that you’re hesitant to tell your neighbors the truth about your contractor. There are asymmetries in the way we think about risk and harm — about a diffuse possibility of injury to many versus a specific injury to one. Social psychologists discuss this in terms of the “identifiable victim effect.” If a vaccine harms one specific person, even while, statistically, it diminishes the risk of harm to millions, we’re inclined to fixate on the specific person harmed. There are also asymmetries in the way we think about harms that result from our actions and harms that result from our inactions. In one study, subjects were reluctant to vaccinate a hypothetical child when they were told that the vaccine could cause death — even though it was explained that the child was much more likely to die from the disease that the vaccine prevented. This “omission bias” suggests we feel that we own certain harms (those our actions cause) and not others (those we could have prevented).