This is to address a posted question here..."do people ever get fired or let go from Big 4and for what reasons?"
Yes, people do get fired, and this is pretty much for the same reasons anyone gets fired from a company. Wrongdoings, Extended unexplained absences, etc. I know of a person who got fired for being "caught in the act" at work. If I were to go into it in detail, this would turn into an adult entertainment blog. Another kid got fired for complete disrespect of authority. And there are quite a few other instances that led to different firings at the big 4.
Now this is where it gets interesting. For my firm for example, it really depends on the region. In some regions, there are a decent amount of clients and the firms are desperate for people, like in the east coast of the US. In some regions, like the southern states, layoffs have occured due to a lack of enough clientele to keep them busy through the year. The new term that hr uses nowadays is "counseled out", wherein our counselors, or mentors within the firm (each individual gets mentors within the firm when they start) call them in and essentially tell them why they're being laid off. One kid got counseled out for a lack of quality effort on his part. They essentially had to weed out a few personnel to get their revenues and expenses to balance out on the profit side.
I don't want to jinx it, but in my case for example, I could go up to the partner and punch him in the face, and i'd probably get taken off his clients, but I won't get fired since they need me. And believe me, I'm not saying this because I might be good at what I do, any fool who's in a senior position or higher will probably be treated the same as me. Firms are going out and hiring extremely aggressively these days even though the economy is in doldrums.
That's probably one of the best things about this field. If job security is your highest priority when looking for a job, this is it. I'd highly recommend public accounting. Why? Because unlike investment banking, it is not deal-oriented. We get a steady stream of income from existing clients and clients do not drop us that often. For a company to drop a big 4 accounting firm, it must have a valid reason. Investors will be suspicious if companies switch auditors. So as startups and other growth companies need "name-brand" auditors to get bigger loans, the big 4 get more clients and thus more revenue. As much as people whine about this job, job security is usually at the bottom of the list of complaints.