What is the key reason why international collaborations can be challenging?

Language barriers and cultural differences among collaborators can make communication challenging

Explanation:

Language barriers such as dialect and language disabilities is the absence of a common language two or more people can communicate with which prevents them from understanding each other through spoken communications. During different scientific collaborations, language barrier has made cooperation between parties difficult. Participants who cannot communicate with the dominate language in such settings could suffer identity conflicts emanating from tension between their professional identity as participants in such international groups.

Cultural differences can also contribute to lack of shared norms and values which in turn reduces trust, effective communication and knowledge transfer in global business setting.  

they can increase to boost the enonomy.

idk if you found them already or not but you probably did but the one closer to sea level is raleigh.