
I wonder how we can build a model that explains why ordinary Russians lie about the presence of their regular troops in Ukraine. It's clear why Khuilo is lying: because he derives utility from deceiving, at least temporarily, other parties, e.g. the UN or some Asian governments who don't understand European politics. Also, he may be trying to communicate a message to Europe and the US that he does not intend to occupy Ukraine "for real". He may also be trying to escape responsibility for war crimes, etc...
On the other hand, it's not clear what kind of utility an ordinary Russian gets from the same lies. Who is s/he is trying to deceive? For what perceived purpose? Is this just, as some have suggested, a show of loyalty to the country and Khuilo as her leader? What's the utility of deceiving oneself? Are they afraid that if they don't follow the official Khuilo line they might get punished (negative utility)?
I think the simplest explanation can be created by considering just two alternative strategies:
1. lying
2. not lying
Obviously, there's no utility in (2) because the person doesn't deal with the situation in Ukraine directly; therefore, there's no incentive for an ordinary Russian to spend any effort on search and evaluation of real data. Basically, we can take a Kahneman view that cognition is expensive. Thus, an ordinary Russian repeats the official lies because for him/her it's the least expensive cognitive option available. Brain (System 1) is lazy and it follows existing biases. As the result, strategy (1) is the most cost–effective because it doesn't cost anything, while providing at least a minimal utility.
To test the hypothesis we could do a survey that measures adherence to official lies depending on the proximity of individual, on either side, to real action. The assumption is that the closer one is to the real, the greater the utility of real data. For example, a Russian soldier ("бурят Шредингера") knows for sure that he is going to be deployed in Ukraine to fight "укрофашистов" as part of a broader Russian military operation.
upd: in systems where lying is cheap, e.g. no political or other competition, people will repeat official lies because it's easy.