This still does not deal with the "not serious" and the "personality disordered". What about the inefficient havoc that they wreak? This, after all, is part of what is known, in legal parlance as: "force majeure".
Note
There is a raging debate between the "rational expectations" theory and the "prospect theory". The former - the cornerstone of rational economics - assumes that economic (human) players are rational and out to maximize their utility (see "The Happiness of Others", "The Egotistic Friend" and "The Distributive Justice of the Market"). Even ignoring the fuzzy logic behind the ill-defined philosophical term "utility" - rational economics has very little to do with real human being and a lot to do with sterile (though mildly useful) abstractions. Prospect theory builds on behavioural research in modern psychology, which demonstrates that people are more loss averse than gain seekers (utility maximisers). Other economists have succeeded to demonstrate irrational behaviours of economic actors (heuristics, dissonances, biases, magical thinking and so on).
The apparent chasm between the rational theories (efficient markets, hidden hands and so on) and behavioural economics is the result of two philosophical fallacies which, in turn, are based on the misapplication and misinterpretation of philosophical terms.
The first fallacy is to assume that all forms of utility are reducible to one another or to money terms. Thus, the values attached to all utilities are expressed in monetary terms. This is wrong. Some people prefer leisure, or freedom, or predictability to expected money. This is the very essence of risk aversion: a trade off between the utility of predictability (absence or minimization of risk) and the expected utility of money. In other words, people have many utility functions running simultaneously - or, at best, one utility function with many variables and coefficients. This is why taxi drivers in New York cease working in a busy day, having reached a pre-determined income target: the utility function of their money equals the utility function of their leisure.
How can these coefficients (and the values of these variables) be determined? Only by engaging in extensive empirical research. There is no way for any theory or "explanation" to predict these values. We have yet to reach the stage of being able to quantify, measure and numerically predict human behaviour and personality (=the set of adaptive traits and their interactions with changing circumstances). That economics is a branch of psychology is becoming more evident by the day. It would do well to lose its mathematical pretensions and adopt the statistical methods of its humbler relative.
The second fallacy is the assumption underlying both rational and behavioural economics that human nature is an "object" to be analysed and "studied", that it is static and unchanged. But, of course, humans change inexorably. This is the only fixed feature of being human: change. Some changes are unpredictable, even in deterministic principle. Other changes are well documented. An example of the latter class of changes in the learning curve. Humans learn and the more they learn the more they alter their behaviour. So, to obtain any meaningful data, one has to observe behaviour in time, to obtain a sequence of reactions and actions. To isolate, observe and manipulate environmental variables and study human interactions. No snapshot can approximate a video sequence where humans are concerned.
[Public Procurement and very Private Benefits]
In every national budget, there is a part called "Public Procurement". This is the portion of the budget allocated to purchasing services and goods for the various ministries, authorities and other arms of the executive branch. It was the famous management consultant, Parkinson, who once wrote that government officials are likely to approve a multi-billion dollar nuclear power plant much more speedily that they are likely to authorize a hundred dollar expenditure on a bicycle parking device. This is because everyone came across 100-dollar situations in real life – but precious few had the fortune to expend with billions of USD.