Decision-making in the world of the Wall is rife with moral hazard; one party engages in a risky or harmful behavior, knowing that another party will have to bear the consequences of that behavior. The moral hazards Lanchester explores in The Wall are related to who has to pay the cost for climate change.

Lanchester uses the conflict between Joseph Kavanagh and his parents to show that the Change is the result of a moral hazard: The consequences of older adults not acting to rectify climate change are borne by people like Kavanagh. Kavanagh describes the atmosphere of guilt and anger that poisons his relationship with his parents. When parents make arguments from experience, the response of the Joseph Kavanaghs of the world is to say: “Why don’t you travel back in time and un-fuckup the world and then travel back here and maybe then we can talk” (54). Kavanagh and his generation reject the moral authority of their parents’ generation. To add insult to injury, people who are the age of Kavanagh’s parents are too old to serve as border defense, leaving young people to pay with their lives for the consequences of previous generations’ inaction.