MBB vs Big Four: Which One Should You Choose?

The consulting industry's three most prestigious firms - McKinsey & Company, Boston Consulting Group, and Bain & Company - are generally called MBB or the Big Three. Meanwhile, the Big Four is referred to as the four largest accounting firms by revenue - Deloitte, EY, KPMB, and PwC - which also have a substantial presence in the consulting industry. 

Although there are differences between each firm of MBB and the Big Four, MBB firms are more similar to each other, as are the Big Four firms. Therefore, this article will compare the MBB and the Big Four as two universal entities under five notable criteria: Size and prestige, Area of focus, Compensation, Career opportunity, and Culture.

Overview of MBB - McKinsey, BCG and Bain

Read more: MBB Consulting Firms Comparison

McKinsey & Company, Boston Consulting Group (BCG), Bain & Company - colloquially called MBB or The Big Three - are considered the three most prestigious firms in the management consulting industry. 

McKinsey is considered to be more prestigious than BCG and Bain. McKinsey & Company also has the most employees and the highest revenue, followed by BCG and Bain. Its personnel reimbursement also reflects those - McKinsey’s personnel usually get better salaries and benefits than BCG’s and Bain’s. 

M – McKinsey & Company

Founded in 1926, McKinsey is the oldest and the most prestigious firm of the Big Three. McKinsey is renowned for its efforts to build high-performance, data-driven, efficient problem-solving.

The company is also famous for its “one-firm” principle, which rigorously incentivizes the sharing of best practices, revenue, and human resources across offices. This principle enables McKinsey to assemble the best people for any given task across any office worldwide.

These two mutually supportive strategies, combined with high salaries and benefits, have consistently strengthened McKinsey’s reputation as one of the best consulting firms to work for.

B – Boston Consulting Group

Founded in 1963, Boston Consulting Group (BCG) is a pioneer in thought leadership, embracing a transformational approach to problems through leading-edge management consulting, technology and design, and corporate and digital ventures.

Maintaining a top-ranked leadership consulting reputation is what sets it apart. BCG’s famous slogan is “Unlocking the potential of those who advance the world”.

The hierarchy at BCG is considered a flat structure, which is not as top-heavy as McKinsey's. This made BCG an excellent choice if you want to work in a supportive, caring system, with valuable opportunities for outstanding mentorship and talent development.

B – Bain & Company

Bain & Company was founded by Bill Bain, former vice president of Boston Consulting Group, in 1973. 

What sets Bain apart is its customer-centric approach to doing business, which focuses on client results rather than reports. 

Bain has cultivated a frat-like mentality among all its employees, defined by the motto “A Bainie never lets another Bainie fail”. Bain is an excellent choice if you want to work in a supportive environment with a flat hierarchy.

Overview of The Big Four - Deloitte, EY, KPMG, PwC

Read more: The Big Four consulting firms

The Big Four firms – Deloitte, EY, KPMG, and PwC – are the world's four largest professional service networks, with a substantial presence in various business areas: auditing and accounting, advisory and consulting, tax, risk and legal advice, etc. 

Originating from the accounting industry, the Big Four dominate the field, which made them initially referred to as the Big Four accounting firms. Later, because of their strong presence in the consulting field, they are also called the Big Four consulting firms (not including any Big Three/MBB consulting firm).

While less prestigious than their MBB counterparts in consulting, Big Four firms earn higher revenue and maintain a much larger workforce. The majority of the revenue of all Big Four firms comes from consulting services, along with legal and tax advisory. 

Big Four firms also have a much broader presence worldwide than the MBB firms, especially in developing and under-developed countries.

Deloitte Touche Tohmatsu

Deloitte has the oldest history among the Big Four firms, when William W. Deloitte opened an independent accounting office in 1845 in London. The current Deloitte was formed in 1989, when Deloitte Haskins & Sells merged with Touche Ross in the US to form Deloitte & Touche, later renamed Deloitte Touche Tohmatsu in 1993.

Through many mergers and acquisitions, Deloitte is now considered the largest multinational professional services network, with a majority of revenue from consulting services, along with legal and tax advisory.  

In 2013, Deloitte acquired Monitor Group consulting firm and renamed it Monitor Deloitte as the firm's strategic consulting arm. However, unlike their counterparts at PwC (Strategy&) and EY (EY-Parthenon), Monitor remains more dependent on its parent firm. 

PricewaterhouseCoopers International

In 1989, PricewaterhouseCoopers (PwC) is created when Price Waterhouse merged with Coopers & Lybrand. PwC is considered to be the second-largest multinational professional services network behind Deloitte, with a majority of revenue from consulting services, along with legal and tax advisory.  

The roots started in 1849, when Samuel L. Price founded an accountancy practice in London, later known as Price Waterhouse. Price Waterhouse's development history until the merger in 1989 is different from the three other Big Four, for the worldwide practice of Price Waterhouse until then was a federation of collaborating firms that had grown organically rather than as a result of international mergers.

In 2013, PwC acquired the Booz & Company consulting firm, renamed it Strategy&, and incorporated the firm into the PwC network as an independent strategic consulting arm. 

Ernst & Young Global

Ernst & Young (EY) was formed in 1989 through the merger of Ernst & Whinney and Arthur Young & Company. Its oldest roots began in 1849 as an English accountancy practice. 

Through many mergers and acquisitions, EY has become a multinational professional services network, with a majority of revenue from consulting services, along with legal and tax advisory.  

In 2014, EY acquired The Parthenon Group to bolster its consulting arm. EY-Parthenon now coexists independently alongside EY’s Consulting division. 

KPMG International

KPMG was formed in 1987 as a result of the merger of Klynveld Main Goerdeler (KMG) and Peat Marwick. Its roots also traced back to the late 19th century. 

Through many mergers and acquisitions, KPMG has become a multinational professional services network, with a majority of revenue from consulting services, along with legal and tax advisory. 

KPMG is generally considered the smallest both in size and revenue of the Big Four, and unlike three other Big Four firms, KPMG does not possess an independent strategic consulting arm. However, KPMG is still one of the most prestigious consulting names. 

MBB vs Big Four - Size and prestige

MBB firms are the most prestigious firms in the consulting industry, followed by the Big Four consulting firms (and their extensive consulting arms) with some other notable Tier 2 consulting firms. 

However, MBB firms' worldwide reach is smaller, and their total revenue is lower than Big Four firms.

The contrast in worldwide reach and revenue versus the prestige of MBB and Big Four is because of the more “elite” status of the MBB – they work in top-tier projects that cost a massive amount of money and resources. Therefore, not everyone is ready to approach them.

Meanwhile, Big Four firms work for more clients on many lower-paid projects, which, combined with their prestige, makes them more approachable while still earning a larger total revenue from more projects.

MBB firms are the most prestigious

According to Vault, in North America, the three MBB firms are the three most prestigious firms. Meanwhile, Deloitte stands at rank 4th, PwC Advisory at 6th, EY Consulting Practice at 9th, and KPMG Advisory at 12th. The positions might differ in other regions, but as long as MBB firms exist there, their top place on the prestige ladder is indisputable. 

Table 1: Most Prestigious Consulting Firms in North America - Source: vault.com

Big Four firms have a larger number of offices and personnel

Each Big Four firm has around 600-800 offices and 200,000-300,000 employees worldwide. In comparison, the most far-reaching MBB firm – McKinsey – only possesses over 130 offices and 35,000 employees.

Table 2: Big Four firms by office and personnel size, 2022

Table 3: MBB firms by office and personnel size, 2022

Big Four firms' revenues are higher than MBB firms

In 2022, Big Four consulting practice with the lowest revenue is EY, earning 13.9 billion USD. Meanwhile, McKinsey - the firm with the highest revenue among MBB - only made a 12.5 billion USD revenue in 2022.

MBB vs Big Four - Area of focus

While all the MBB and Big Four firms have a substantial presence in many industries, the MBB firms are more famous for their reputation in strategic consulting, while the Big Four firms compete more in accounting and operation consulting. 

However, MBB firms are also renowned in operation consulting, as clients who hire an MBB firm for a strategic consulting project will hire them again for the implementation process. 

MBB firms concentrate on strategic consulting

This also reflects that MBB firms work with “elite” status. Many Fortune 500 companies and government institutions hire MBB consultants on some of the most important projects.

In return, they will want the most critical consultation and ideas, which MBB consultants usually do as well as expected. After those high-class clients get some good consultation on an important problem, they usually hire that MBB firm again for the implementation process. 

This relationship benefits both sides: Clients get good ideas for their most challenging problems, while MBB consultants are remembered for their outstanding performance. And that is how MBB firms build their prestige on strategic consulting for a long while. 

Big Four firms concentrate more on accounting and operation consulting

The Big Four consulting firms originate from the Big Four accounting firms, so their prestige in accounting consulting is indisputable. MBB firms will have to step behind the Big Four in this field.

On the other hand, while hiring MBB consultants seems like a brilliant idea, the price is usually too high for many. Besides, not everyone gets the problems that they consider “too hard” to deal with every time.

This is where the Big Four firms fill in: they have the prestige, the price is more considerable, and for the client the problems are not that “hard”. Therefore, the Big Four are more likely to be hired for operations consulting.

Furthermore, three Big Four firms have strategic-focused consulting spin-offs that act more or less independently of their mother firms: Deloitte has Monitor Deloitte,  PwC has Stategy&, and EY has EY-Parthenon. Those spin-offs compete with MBB firms in strategic consulting, with Strategy& and EY-P gaining more notable successes.

MBB vs Big Four - Compensation

Read more: Top consulting firms salaries

In general, MBB firms pay their consultants more generously than the Big Four firms. MBB consultants also have access to better perks, benefits, and personal support. This also reflects the status and prestige of each firm in the consulting field. 

For example, in the United States, consultants in both groups are paid roughly the same amount of annual base salary - usually around $70,000-$90,000 for junior consultants and $90,000-$130,000 for senior consultants.

However, when combined with bonuses and profit sharing, the gap between MBB and Big 4 consultants' annual earnings widens sharply. Furthermore, the fringe benefits offered by the MBB are generally more comprehensive and generous compared to the Big Four consulting firms.

All three MBB firms enjoy a vast amount of top-tier benefits in the industry, including (but not limited to) health insurance, life insurance, tuition assistance, childcare reimbursement, employee discounts, employee stock options, and using company-owned vehicles for personal use. 

While Big Four consultants' perks and benefits are less luxurious than in MBB, they still enjoy outstanding quality and quantity of service compared to the rest of the consulting industry.

MBB vs Big Four - Career opportunity

Aside from the prestige of being an MBB or a Big Four consultant, the learning opportunities and the exit options are very lucrative. However, if you are an ex-MBB consultant, you are exposed to better opportunities and networks in the future.

Of course, being an ex-consultant from a Big Four firm still means you are a lot more prestigious than most of the industry and, therefore, exposed to many good post-consulting choices.

Internal career progression

Career progression will look slightly different depending on which firm you are working for. Take a look at the summary below.

Of course, each firm will have its own initiatives for moving employees up and down the ladder. However, all three share the same rule of thumb: Up-or-Out! This means a consultant has to climb up to a better position in a certain amount of time. Many consulting firms practiced this system to promote a competitive environment for their personnel.

MBB prestige leads to better exit opportunities for consultants… 

Fortune 500 personnel are full of ex-MBB consultants. Many Fortune 500 companies and government institutions hire MBB consultants. Through this, consultants establish an extensive network with key personnel of client firms who know the formers' capabilities, which opens up some great exit options for ex-MBB consultants. 

Even when you do not choose to work for your old clients, if your resume shows that you are an ex-MBB consultant, it radiates credibility and prestige in the eyes of future recruiters or clients. 

… but coming from the Big Four still means you have better exit options than most 

On the other hand, an ex-Big Four consultant might not have such great chances as an ex-MBB one since their target market is more mass than the “elite” market of MBB firms. This leads to a “weaker” network an ex-Big Four consultant might have with key personnel of the most significant institutions and firms in the region. 

However, the prestige and level of work of Big Four firms mean their consultants still get massive respect from people from many industries, which opens up many great choices for an ex-Big Four consultant. 

MBB vs Big Four - Culture

“Up-or-Out” culture

A good consultant always has a high-achieving mindset and who cannot continuously strive for excellence will have to step aside. This became the basis for the “Up-or-Out” culture: a consultant has to climb up to a better position in a certain amount of time. 

Many consulting firms, most notably the MBB and Big Four, practice this system to promote a competitive environment for their personnel. 

MBB is more "elite" than Big Four

There are two main reasons that can explain why MBB’s consulting culture is more “elite” than Big Four’s.

First, the requirement for a candidate to enter MBB firms is more demanding, and many great candidates also prioritize joining MBB firms as the first step to kickstarting their careers.

Second, consider the great prestige, excellent benefits, and potential clients an MBB consultant has compared to a Big Four consultant - all of them must translate into significant results. 

And finally, combine the two above: the greater prestige and benefits attract better candidates, and better candidates become consultants making a firm more prestigious in return. This is how MBB firms have kept themselves on top of the game for a long while.