Final answer:
Collaboration is an important factor that can increase the surplus provided by a third party through synergy, shared resources, and improved competitiveness.
Step-by-step explanation:
An important factor that affects the increase in surplus that a third party provides can be attributed to several factors, including but not limited to changes in the cost of inputs, natural disasters, new technologies, and government decisions. Each of these elements can influence the cost of production, which then impacts how much firms are willing to supply at any given price.
However, when evaluating the specific options given in the question, collaboration stands out as it entails different entities working together to achieve a common goal which often leads to synergy and, therefore, an increase in surplus. This collaboration can reduce risks, decrease costs through shared resources, and enhance the competitiveness of the goods and services provided.