Should I take a 40% pay cut to change jobs?

I totally identify with that fight-or-flight instinct, but this sounds like out of the frying pan, into the fire. Use the fact that you actually have a job as a tool to score one that is actually worth switching to.

Not too long ago I took a job that was a 30+% cut in total compensation. It was a more fulfilling job that I lasted less than a year in before returning to a former employer. Either way I was very well paid but the difference in terms of after-tax cash-in-vs-cash-out was something that I was reminded of twice a month. Big big questions to ask yourself: 1. are you the main source of income for your family? 2. are you independently wealthy? 3. are you at the end of your current career or the beginning? 4. would you rather sock away another few years of good money and then pursue this? Btw, you are very, very, very unlikely to get a 66% raise (getting you back up to 100%) after one year.

HUH? "There is considerable risk in going for the new job, regardless of the money. It will probably involve longer hours (around 12 hour days; I know someone who works there) which is part of the reason I want to leave my current job. I want to get my life back and have hobbies again." This makes no sense. Please clarify.

OK, what I'm hearing from you is desperation -- you so want out of the current job you'd consider working longer hours for far less pay. There is one and only one reason to take a job working longer hours for far less pay: The new job fits your lifelong passion. You're quitting a mid-level manager position to become a teacher, for example. I had a friend who did just that, in fact. Quit as an accountant to teach elementary school and took a brutal pay cut in the process (exacerbated by the cost of going back for a teaching certificate). But he's happy, he loves the kids, and he's found his passion. I don't hear that out of you. I hear this is something you might like more. And that's not a reason to take a huge pay cut. Throw it back. You're better than this.

I was in this situation, and decided not to do it. It is not just the financial impact of the huge pay cut that you have to think about. You're going to get paid less than you're worth, and that's something that's bad for your career and bad for your long-term earning potential.

I did this about ten years ago when changing industries and it was one of the best decisions I've ever made. I work in an industry where I'll never be rich, but I am incredibly happy. Totally worth it. But, I'm not seeing that here. It seems like you are lukewarm about the new option. If that's the case, maybe it's not the best decision to increase your hours and decrease your pay for something that you don't flat-out love. Unless of course your current job is making you actively depressed/anxious which I kind of get a hint of from the phrase "desperate and trying to escape". Your well being always wins out over disposable income. Or it should anyway. Life is too short to spend it miserable. You can make dinner at home with your girlfriend and still be happy.

This was your first application and interview in the field you want to transition to, right? I think you need to interview at a few other places. Are you learning all new skills or do some of your skills transfer to the new field? Is the lower pay typical in the new industry or does this one company treat it's employee's poorly? Can you ask for an hourly position instead of salary so you can get overtime? I think you should keep looking and choose a job you want to do instead of choosing a job as an escape from what you currently do.

The only way the second work option would be worth the 40% pay cut is if the workplace were right next door to you. You don't mention the commute involved, either in your current job, or the hypothetical new one. Please keep looking. And look closer to where you live, if possible.

On top of all the other sensible things that people have already said, I would add only this... I know she would say she doesn't care about those kinds of things, but I know it makes her happy. Let other people be the judge of what's important to them. For example, I might enjoy going out for a nice meal every weekend, and nice meals certainly make me happy. And yet if it was a choice between my partner being miserable in their high paid job, and us not having so many fancy dinners, well that's a no brainer. Partner's happiness wins every time. More than that, I'd get a warm glow from helping them make that change that would outweigh any number of fine dining experiences. However if my partner said what you've said here, I'd be concerned that they're probably not actually going to be any happier in this new job than the old one.