While I agree that using percentages would make impact more comparable between agents and timesteps, it also leads to counterintuitive results (at least counterintuitive to me)
Consider a sequence of utilities at times 0, 1, 2 with U0=1 , U1=0.01 and U2=0 .
Now the drop from U1 to U2 would be more dramatic (decrease by 100%) compared to the drop from U0 to U1 (decrease by 99%) if we were using percentages. But I think the agent should ‘care more’ about the larger drop in absolute utility (i.e. spend more resources to prevent it from happening) and I suppose we might want to let impact correspond to something like ‘how much we care about this event happening’.
While I agree that using percentages would make impact more comparable between agents and timesteps, it also leads to counterintuitive results (at least counterintuitive to me)
Consider a sequence of utilities at times 0, 1, 2 with U0=1 , U1=0.01 and U2=0 .
Now the drop from U1 to U2 would be more dramatic (decrease by 100%) compared to the drop from U0 to U1 (decrease by 99%) if we were using percentages. But I think the agent should ‘care more’ about the larger drop in absolute utility (i.e. spend more resources to prevent it from happening) and I suppose we might want to let impact correspond to something like ‘how much we care about this event happening’.
That would depend on whether things have a multiplicative effect on utility, or additive.