See e.g. a nice paper by Matthew Rabin which quantifies the extent to which diminshing marginal utility is too weak an effect to explain actually-observed risk aversion, by proving statements like this: “If you would turn down a 50:50 gamble between gaining $101 and losing $100 on account of diminishing marginal utility, then you would also turn down a 50:50 gamble between gaining all the money in the world and losing $10,000.”
See e.g. a nice paper by Matthew Rabin which quantifies the extent to which diminshing marginal utility is too weak an effect to explain actually-observed risk aversion, by proving statements like this: “If you would turn down a 50:50 gamble between gaining $101 and losing $100 on account of diminishing marginal utility, then you would also turn down a 50:50 gamble between gaining all the money in the world and losing $10,000.”