Please explain the relevance of this document from the 2006 World History AP Exam.Souce: Tomas de Mercado, Spanish scholar, Manual of Deals and...

This document is written from the point of view of a
Spaniard who would have been thinking about the economic situation of the time in which
he was living.  The point of the document is that the Chinese were selling all sorts of
goods to the Spanish in the Philippines and were buying nothing from
them.

Remember that this question is asking you about the
flows of silver during this time -- about their economic and social effects.  This
document (and you should compare it to Document 4) is making the point that all of the
silver is flowing in to China and none is coming back out.  This was a major issue for
the Europeans at this point in history since they believed in mercantilism and the need
to have a favorable balance of trade with bullion flowing into your country rather than
out of it.

The point of the document, then, is that (from
the Spanish point of view) the trade with China was too one-sided, causing the Spanish
to lose silver to the Chinese.