Statistics need context

The studies you quote - about 3% of successful businessmen leaving their wives for their affair partners, and elsewhere 10% of married people divorcing to marry their lovers, of which 70% go on to divorce - refer to the Halpin study.

To put the Halpin 3% into context: It is not 3% of married men who leave their wives and marry their lovers. It is 3% of her sample who willingly admitted having married their former lovers and who were still married after 5 years... which could be extrapolated, using the other study as a guide, to refer to the 30% of such marriages which last (or at least, last longer than five years); resulting in a figure of "those who leave to marry their lovers, but divorce within 5 years" of 10%.

Divorce rates on subsequent marriages - whether infidelity was involved in the first marriage or not - do tend to run at around the level cited in the Staheli study (figures range between 60 - 85%), so the impact of the infidelity in the previous marriage is pure speculation, since the chances of success of that marriage are the same for any subsequent marriage with or without infidelity. And with divorce rates from first marriages at around 50% anyway, that's not that much of an increase in the chances of failure.

I'm assuming these studies were conducted in America, where attitudes toward infidelity are highly intolerant (in terms of views expressed, rather than actual behaviour - which suggests otherwise). For respondents to admit to interviewers that they left for an affair partner breaks taboos. It may be fine for successful businessmen to boast about their many affairs - it's part of the virility associated with the role; presumably the interviewer had no way of correlating claims with evidence to ascertain whether their extramarital extravaganzas took place in the real world or their imaginary world, or to what extent - but it's not fine to admit that you've betrayed your duty and responsibility as a provider (also keenly linked to virility) by abandoning your family to pursue your love interest. It's a confession too far. I don't know a single man who, having left his wife or family to marry his lover, would admit that to a stranger, especially one with a clipboard (and I know many such - family, friends, colleagues and my own husband).

The statistics show doom and gloom - but anecdotal evidence suggests something else entirely. Among at least some social groupings, first marriages are the stuff of callow youth, the same way that failing first year at university before getting your act together to succeed in the course you really want to study is part of growing up. First marriages are practice marriages - it's the ones you engage in later, when you know who you are and what (and who) you want in life, that last, flourish and fulfill. I've watched my father - who divorced my mother for his lover - blossom over the decades; I've watched my husband learn to enjoy life again; I've seen friends and colleagues reinvent themselves to achieve their dreams; and I've seen "society" turn away and pretend that that doesn't happen, to perpetuate the myth of the nuclear family and the rest of the panoply of conservatism. I guess it's just too threatening to consider that, actually, not everybody is as miserable as oneself.