Eric, all of your suggestions can be true in some cases. In my experience, the reasons for long hours vary quite a bit:1) "Crunch time" on projects - consulting is a project-based business, so consultants are exposed to "crunch time" more often than if they worked in a continuous fashion. Each project is a one-off event for its respective client and so they are keen to go for an extra-ordinary effort, especially as the finishing line approaches. As consultants are premium-priced resources, clients expect (and consultants sell themselves on the basis) that they will be exceptionally productive, motivated and hard-working. Although consultants do have some specialist tools and techniques that boost their productivity, it often comes down to putting in raw hours to churn through the work. Towards the end of a project, there may be some tasks that cannot be easily divided or spread across time (e.g. you can't write the final report until client teams have reported in with their data). In this way, "extra-ordinary crunch time" on the client side can become an "ordinary" event on the consultant side.2) Poor project management - too few resources, too little time budgeted, ineffective communication and leadership styles. A number of firms appoint fresh MBAs without prior experience into project management positions, or promote strong individually-performing Analysts into project management positions (per the "Peter principle"). The assumption is that they can learn on the client's dime and the best project managers will stay on. The knock-on effect is that consultants on the project may have to work long (often unrecorded) hours to make up the time, or may waste time on re-working deliverables to suit a changing brief.3) Improperly incentivised sales - selling without accountability for the profitability or deliver-ability of the work. This takes effect in a similar fashion to the poor project management described above, but originates further upstream. In some firms, partners, client relationship managers, or other dedicated salespeople will work independently of the project manager and delivery team to develop their proposal to the client. They may over-promise, may not have experience or deep knowledge of the work, or in the heat of competition/under pressure of the economy, may consciously under-price work in order to notch up a win on their sales tally. There is rarely a "claw-back" clause, and sales targets are often based on headline revenues rather than the profitability of the work.4) "Face time" culture - under which consultants are evaluated according to their presence in the office/at company events rather than by their productivity. This is more commonly found in banking where the team is permanently office-based, rather than in consulting where the team may be spread across a large area during the week. However, "face time" is particularly found at firms where a strong and homogeneous culture is an important part of the firm's selling points. The long hours spent at work may not be spent continuously working and may not be intensive - consultants may work until 6pm, go out for dinner together until 9pm, return to the office and continue working until 11pm, go for drinks until 1pm, then go home and send an email or two. In these more cost-conscious times, dinner and drinks may be replaced by take-out and surfing the internet (or sitting in a taxi on the way back from the client site). Even where consultancies have instituted "home working" policies, at some firms there is a culture of monitoring IM online status and it is expected that anyone working from home is still sending regular emails to the team. Obviously, all of this has an effect on productivity, and the moral of the story is that total "working" hours don't tell the whole story.5) Individual bravado - where individuals take pride in demonstrating their ability to leave work until the last minute and complete it under pressure without a team. This can be common in firms which hire large numbers of fresh engineering graduates, who bring the "expert loner" attitude with them. You might think that working in teams with a large number of similar people would lower the barriers to delegation and teamworking. However, it actually serves to exaggerate the effect because of the perceived need to outperform the "competition". Therefore, work is concentrated on a few resources rather than "levelled" across the available pool. Those few resources need to put more hours in to complete the work. A great study of this attitude and its effects can be found in the <a href="http://journals.aomonline.org/inpress/main.asp?action=preview&art_id=458&p_id=1&p_short=AMJ">Academy of Management Journal</a>.All of these factors play some part in all consultancies and they interact. For example, you might get factors 4 and 5 playing a strong role in some firms: a few people working hard late into the night, while the rest of the team hangs around until they're done. At other firms, only factor 1 may play any significant role, so people only work late on the last few days of a three month project.
