Some countries import a large amount of food from other parts of the world. To what extent is this a positive or negative trend?

In many countries today, people in cities either live alone or in small family units, rather than in large, extended family groups. What are the reasons for this ? Is this a positive or negative trend?

Fewer students are studying science at school and university, favouring more computer-based subjects instead. Is this a positive or negative development? What are the reasons for this?

Some universities now offer their courses on the Internet so that people can study online. Is this a positive or negative development?