What is the three (more if you like) fundamental economic reasons for the ACA act?

What is the three (more if you like) fundamental economic reasons for the ACA act? There are more than three but emphasize your perceptions of the reasons for these three (hopefully you pick your most important three). You should use other sources (including Santerre/Nuen) to understand the intent of the ACA. Note: Remember to utilize MSB vs MSC and unintended consequences.
Following along with the idea of the three reasons, there was an original economics saving (or cost) to implement the ACA and since that time the economic impact has changed. Analyze the impact of the changes. This is the most important part of the paper.
Since health care is not an exact science, comment of the intended social and economic benefit from the bill in long term.
Summarize your findings.