Presumably, there are many places where PhD fees are waved and where many students receive some form of scholarship/stipend/wage. Thus, it seems that there are several issue:

• Are fees waved, deferred, or paid:
• Do you get given money to do the PhD and if so how much?
• Are you considered an employee and therefore get additional benefits?
• How much additional work (e.g., teaching, research assistant, etc.) is allowed or advised while doing PhD and how much money does that generate?
• What are you defining as the income you could earn in industry and how close do you have to get to that income for the PhD to be considered equivalent?

I'll use the case of a PhD in Australia as an example:

• Most local students will have their fees waved
• Perhaps half of all PhD students are on a scholarship
• The median wage of a full-time worker is about AUD$60,000, which at a guess is roughly $48,000 after tax.
• A PhD scholarship would be about AUD$26,000 after tax
• If you did some tutoring work up to the generally allowed level (perhaps 6-8 hours per week averaged throughout the year) you might earn another AUD$10,000 which wouldn't be taxed because you're below the tax free threshold.

So, in summary, you are earning $36,000 gross compared to median wage of about $48,000. You're not getting retirement benefits and many of the other employment benefits you would get with a full time wage.

Alternatively, you might be able to work part-time and do the PhD part-time. Many scholarships require full-time completion. But if you are able to get scholarship and work part-time. Then you might be able to put together something approaching median wage. That said, the whole process would take longer, and you wont necessarily be in a better financial position at the end, had you gone part time, and started your post-PhD career sooner.

So in summary, I guess it depends on exactly where you set the frame of reference and how you combine scholarship, other income, and the potential post-PhD income.

Presumably, there are many places where PhD fees are waved and where many students receive some form of scholarship/stipend/wage. Thus, it seems that there are several issues:

• Are fees waved, deferred, or paid?
• Do you get given money to do the PhD and if so how much?
• Are you considered an employee and therefore get additional benefits?
• How much additional work (e.g., teaching, research assistant, etc.) is allowed or advised while doing PhD and how much money does that generate?
• What are you defining as the income you could earn in industry and how close do you have to get to that income for the PhD to be considered equivalent?

I'll use the case of a PhD in Australia as an example:

• Most local students will have their fees waved
• Perhaps half of all PhD students are on a scholarship
• The median wage of a full-time worker is about AUD$60,000, which at a guess is roughly $48,000 after tax.
• A PhD scholarship would be about AUD$26,000 tax free.
• If you did some tutoring work up to the generally allowed level (perhaps 6-8 hours per week averaged throughout the year) you might earn another AUD$10,000 which wouldn't be taxed because you're below the tax free threshold.

So, in summary, you are earning $36,000 after tax compared to median wage of about $48,000 after tax. You're not getting retirement benefits and many of the other employment benefits you would get with a full-time wage.

Alternatively, you might be able to work part-time and do the PhD part-time. Many scholarships require full-time completion. But if you are able to get scholarship and work part-time. Then you might be able to put together something approaching median wage. That said, the whole process would take longer, and you wont necessarily be in a better financial position at the end, had you gone full-time, and started your post-PhD career sooner.

So in summary, I guess it depends on exactly where you set the frame of reference and how you combine scholarship, other income, and the potential post-PhD income.