On Bootstraps
Lots of comments calling the math into question. I had some fun trying to understand the objections and learned a few things. We are dealing with 15 shillings a week or 780 shillings a year. There are 20 shillings in a pound so that’s £39 per year.
In 2020 money, that’s £5,067.37 per year^{1}. We know that Bob worked six days a week. Assume ten hours a day. That’s 60 × 52 weeks = 3,120 hours per year.
Using the typical 2,080 person hours^{2}
Then, back in 1843 (when A Christmas Carol was published):

20 shillings = ￡1 makes 15 shillings = ￡0.75

He works 6 days a week and

￡1 back then is ￡129.93 ≅ ￡130 now. This means that ￡0.75 back then ≅ ￡98 now.

￡98 per week, six days out of the week = ￡16.33 per day

￡16.33 per day, 8 hours per day ≅ ￡2 per hour

With the current conversion rate, ￡2 per hour = $2.7 per hour
$2.7 per hour is significantly worse than the current minimum wage of $7.25 per hour.
However, simple income adjustments are not the whole story! And I think that’s what the commenters appear to miss. One must factor the purchasing power of a dollar around 180 years ago.
You get a sense of the purchasing power of a dollar in 2021 compared to say 2000 by subtracting the cumulative change in inflation rates for 2021, which is 348%, and 2000, which is 301%. In this example, the difference is 47%. So a $1 in 2000 is worth $1.47 now.
The Bureau of Labor Statistics has a CPI Inflation Calculator that only goes back to 1913 (so 70 years of missing data.) If you plotted the changes in inflation rates, you’d get a mess of a graph that’s very hard to extrapolate back to 1843 (because economies are complex and sensitive things and a lot of unpredictable shit can happen.)
So what to do? Let’s say you worked (unlikely, and especially so if you worked for Scrooge.) At $2.70 an hour, you made $5,616 per year or
https://babel.hathitrust.org/cgi/pt?id=miun.ajb5449.0001.001&view=1up&seq=164&skin=2021
I really liked this page.
https://www.omnicalculator.com/finance/buyingpower

According to the Bank of England’s Inflation Calculator which, because England, has data going back to 1209. ↩︎

40 hours a week, 52 weeks a year. ↩︎