90% of MBA graduates are employed within three months and most are earning 60% more than previously. Should you take an MBA, therefore?

The Economist has produced its ranking of the top 20 MBAs.

If you're thinking of reinvigorating your financial services career with a spot of studying this may come in helpful. In terms of European business schools, the Economist ranks IMD first, followed by IESE, followed by London Business School, HEC, ESADE, and INSEAD.

On paper, all these schools look great. Most have 90% or more of their graduates in employment three months after the course finishes (HEC is the outlier on 85%) and their MBA graduates far better off than they used to be. Most are at least 60% better off. At IESE they're 150% better off.

So, if you're already out of work, or expecting to be find yourself out of work imminently, why not enroll for an MBA right away? Not only will you be almost guaranteed employment, but you will benefit from a massive uplift in your compensation.

The first reason is, obviously, fees. It's becoming a lot harder to fund an MBA than it used to be. Neither HSBC nor Citi are providing loans to MBA students any more (which possibly says something about the problems people have been having paying them back). Insiders say schools are cutting course sizes as a result.

The second reason is immigration. Non-EU MBA students are currently able to remain within the UK for two years on a post-study work visa and can then switch to a Tier Two general visa without eating into banks' immigration quotas. But this may change. "The real problem is that no one knows what will happen after April next year," says Jonathan Goldsworthy at law firm Bird & Bird.

The third and biggest reason is the meaningfulness of figures produced by business schools for MBA graduate employment and salary levels. MBA careers services talk of big pressure to get people into jobs within three months in order to look good on rankings such as those produced by the Economist and the Financial Times..

"That three month employment figure has a big impact on business schools' revenues," says one MBA careers advisor. "Schools have been forced to work much harder at making students pragmatic and realistic in order that they will accept the jobs on offer and be in work by the right date."

Equally, salary increases post-MBA can be inflated when a large proportion of students come from low paying roles overseas. "Someone who's earning $40k in India and who finds a role in London is going to get a big percentage increase," points out the consultant.

In their defence, MBA schools say opinionated students can't be compelled to accept unappealing jobs simply to satisfy the three month employment target and that the range of financial services employers looking for MBAs has increased. "Rothschild, Lloyds and Standard Chartered have all expanded their MBA programmes this year," says one MBA careers advisor. "MBA students are still a comparatively cheap way for banks to hire experienced talent," he points out.