Final answer:
The Lovejoy model has issues with quantifying subjective factors like happiness, individuals' varying abilities to measure their own happiness, and relying on inaccurate assumptions about a universal scale of pleasure.
Step-by-step explanation:
One potential problem with the Lovejoy model is that it is difficult to quantify and measure subjective factors such as happiness or pleasure, which the model requires for its calculations. Additionally, the ability to predict how individuals measure their own happiness can vary greatly, making it challenging to use the model accurately in practice. Furthermore, the issue of inaccurate assumptions can arise from the Lovejoy model, such as assuming a consistent scale of pleasure or happiness which can be applied universally across different individuals and circumstances.