1. Unavailability of interpersonal utility comparisons: The cardinal utility theory assumes that the utility of different individuals can be compared and measured on a common scale. However, this assumption is unrealistic as it is not possible to directly observe and measure the utility of individuals.
2. Incommensurability of different attributes: The cardinal utility theory assumes that the utility derived from different attributes of a product or service can be added up to give an overall utility. However, this assumption ignores the fact that different attributes may be incommensurable, i.e. they cannot be directly compared or traded off against each other.
3. Non-satiation assumption: The cardinal utility theory assumes that consumers are never satiated, i.e. they will always prefer more of a good or service. However, this assumption is not always true as consumers may reach a point where they are satisfied with the amount of a good or service they have and do not desire any more of it.
4. Independence of utility: The cardinal utility theory assumes that the utility derived from a good or service is independent of the utility derived from other goods or services. However, this assumption is not always true as the utility derived from a good or service may depend on the consumption of other goods or services.
5. Unrealistic assumptions about consumer behaviour: The cardinal utility theory makes several unrealistic assumptions about consumer behaviour, such as the assumption that consumers are rational and have perfect information. However, in reality, consumers are often irrational and have limited information, which can affect their decision-making process.
Overall, the cardinal utility theory provides a useful framework for understanding consumer behaviour, but it has several weaknesses and limitations that should be considered when using it to explain consumer behaviour.