In absolute amount of pay, we would be middle-class. However, looking at the amount of hours a resident puts in, the pay is more close to minimum wage.
For example- say a first year resident gets $46,000 a year. Divide that by 52, and you get a weekly wage of $884. If you are on an ICU month, then you are probably looking at at least 80 hour work week.
In the real world, you get paid overtime for any hours put in after 40. So, If you work 60 hours, you get time and a half for 20 of those hours. You end up getting paid the equivalent of 70 hours for the 60 hours put in. If you work 80 hours in the real world, you get paid double time for the 20 hours over 60 hours. You get paid as though you had worked 110 hours for your 80 hour work week.
If you spin the numbers this way, you can divide 884 by 110 you get about $8 per hour. That is pretty bad for someone who has 8 years of schooling behind them.
On ER months, you generally work just 60 hours per week. However, add into that the expected research projects, the studying, and coming in from home on your days off to go to lectures (other residencies have lectures during the day and so their hours spent at the hospital include education time), and the true number of hours dedicated to the job is well over 60 hours. Also keep in mind that an 8 hour shift generally turns into a 9-10 hour shift, etc. If you use the above formula, then a 60 hour work week should get paid for 70 hours, taking into account overtime. This would put the hourly wage of an ER resident, while working in the department at around $12 per hour. Again, pretty low for someone with 8 years of education post-highschool.