I would believe any numbers that were objectively presented with sound methodology. Using a single call center study as evidence that worker productivity increases just doesn't make sense. Most work isn't anything like working in a call center.

Here is another misleading claim from that link:

> Working Remotely Can Increase Productivity up to 77%

But they then clarify that "77% of those who work remotely at least a few times per month show increased productivity." Productivity increasing by 77% is not the same as 77% of people experiencing any productivity gain. Also, they link to a source for this claim, but the link takes you to a blog spam page titled "43 Productivity Tools That Will Make Your Life Much Easier." There is no mention of the claim on this page.