The important issue with Warren's "plan" is that it's essentially a $8,000 per year per employee head tax, so it's a regressive tax. An afterthought in the expense of hiring a very highly-paid employee, but a not-insignificant expense of hiring a lower-paid employee.

Not to mention that her plan exempts contractors and business under 50 employees, so it incentivizes businesses to to lean on contract labor or reorganize themselves into smaller sub-companies - a small paperwork expense in the scheme of things.

The business tax should be universal to stamp out avoidance and scaled to all payroll spend so it's at least not regressive, even if it's not a progressive tax.