
One measure of how radically life has improved over the centuries is how much nighttime illumination can be purchased from a certain amount of labor.
For example, George Washington calculated that it cost him £5 a year to provide himself five hours of reading light every evening. That is the equivalent of about $1,000 today.
Imagine spending $83 a month to light only one lamp in your entire house.
We are amazingly rich today.
This insight provided by Human Progress on 2/15/17: How the cost of light has fallen by a factor of 500,000.
Here are some reference points provided by the article: