Hedonic factors have to do with pleasure and pain. It seems to me that the answer to this question depends on how broadly or narrowly pleasure and pain are defined. It may be possible to define pleasure and pain so broadly that we can assume that our preferences are always governed by hedonic factors.
The question becomes more interesting, however, if a narrow definition of hedonism is adopted. Clive Hamilton has a very narrow definition of hedonism in mind when he writes: “The pleasant life, or life of pleasure, is one motivated by hedonism – the desire to maximise the number of emotional and physical ‘highs’ that is the signature of modern capitalism” (“The freedom paradox”, 2008: 12). Hamilton goes on to claim: “The hedonic conception of happiness is the one assumed by the utilitarian approach of neoliberal or free-market economics”.
Once you strip the gratuitous nonsense out of those statements it seems to me that you are left with nothing more than the assertion that the preferences that people reveal in their market behavior reflect only their desire to maximise the number of emotional and physical highs that they experience. That seems to me to be an offensive view to have of the motivations of one’s fellow human beings. If Clive actually observed the market behavior of real people he would see a lot of people making a lot of decisions with a range of motivations, including the longer-term well-being of their families.
Do free-market economists assume that the market behavior of people is motivated solely by a desire to maximise the number of emotional and physical highs they experience? I can’t speak for everyone, but I would be surprised if many free market economists would make that assumption. I imagine that most free-market economists would accept Lionel Robbins view that economists do not have to make judgements or assumptions about motivations: “Why the human animal attaches particular values ... to particular things, is ... quite properly a question for psychologists or perhaps even physiologists. All we need to assume as economists is the obvious fact that different possibilities offer different incentives, and that these incentives can be arranged in order of their intensity” (“An essay on the nature and significance of economic science”, 1945: 86).
Free-market economists believe that whatever motivates the market behaviour of individuals their preferences should generally be respected. My personal view is that individuals are generally capable of making judgements in their own best interests, that no-one else is better placed to make such judgements and that individuals are more likely to flourish when they know that they have to accept responsibility for the consequences of their own judgements. However, I also believe that some contrary views, such as those based on the evidence of irrational behaviour presented by psychologists and behavioral economists, deserve serious consideration (see previous posts on the topics of ‘autonomy and responsibility’ and ‘self control’).