I'm honestly surprised at the amount of pushback against part time work in this thread. When you hire a consultant or contract labor, isn't that basically what you are doing? Bringing in part time labor?
I think a lot of the complaints about it not scaling well (need to pay for two healthcare plans for two part time employees vs 1 full time, etc) also don't make any sense. Isn't money fungible? Who cares who exactly is in charge of the chunk of money that gets spent on healthcare for the employee at the time? Just pay people in cash just like you would another small business you are contracting with, and let the employee use a portion of that cash flow to pay for their healthcare and other benefits programs, just like what happens with the small business you contract with. The rate they quote you to pay them should therefore be including both the cost of their labor and their overhead. In other words, treat these employees like independent small businesses, and all the hand wringing and consternation should just melt away. And who knows, maybe these employees will really run with this small business consultancy model and build and expand their business in their own right.