Then pay them. Make an honest calculation of what it's worth to you, and if you can give them something below that number that makes the candidate happy then everyone wins. If it saves you time (money) then share the wealth.

So candidates who have worked at other companies which have internal source control, you simple think they've never coded before since it's not somewhere you can see? Or you expect that they should be coding at home after having coded all day at the job they have?

No matter what interview process you use to filter out candidates, people will be upset. I actually don't mind doing white board interviews because I find that the pressure is less than peak pressure at an actual job and I don't have to deal with minor API issues.

But I like the idea of homework because you don't need to find an excuse to take a day off from work, especially if you are interviewing at multiple companies.

Portfolio of what? I'm not a graphic designer. I'd love to be able to save great code that I've written over the years. But it's all covered by license agreements, NDA's, security clearance, etc. So unless you're exclusively looking at amateur projects or open source developers, that's not a good business plan.

Right. All my best code (and worst, of course) is owned by my employer and former employers, and is usually exclusively licensed to their customers.

I tend not to code in my off hours any more, because I have different interests now, that require the expenditure of leisure time to enjoy. If I do, it is to solve an immediate need or as a side-project to make money directly, rather than to maybe get another job in the future.

If you want my portfolio, I want to browse your defects database and code repository before we interview.

Strange, the companies I've talked with send the homework out before even looking at my portfolio.

Good luck getting a good engineer