I am familiar with the concept of a utility function, which assigns numbers to possible world states and considers larger numbers to be better. However, I am unsure how to apply this function in order to make decisions that take time into account. For example, we may be able to achieve a world with higher utility over a longer period of time, or a world with lower utility but in a shorter amount of time.
When people calculate utility they often use exponential discounting over time. If for example your discount factor is .99 per year, it means that getting something in one year is only 99% as good as getting it now, getting it in two years is only 99% as good as getting it in one year, etc. Getting it in 100 years would be discounted to .99^100~=36% of the value of getting it now.
Anonymous #7 asks:
When people calculate utility they often use exponential discounting over time. If for example your discount factor is .99 per year, it means that getting something in one year is only 99% as good as getting it now, getting it in two years is only 99% as good as getting it in one year, etc. Getting it in 100 years would be discounted to .99^100~=36% of the value of getting it now.