[rskar]

The words "reason" and "explanation" are nearly synonymous. (I went to http://www.merriam-webster.com/dictionary to be certain of this.) If anything, an explanation is built from a set of reasons.

So refurb gave a reason for a bottleneck, and now we need to figure out why providers apparently aren't taking steps that address it.

[cmdrfred]

The same reason IT guys oppose H1B visas? They like their earnings right where they are thank you.

[maxerickson]

reason(1), explanation(2).