Sentence 1: The idea of a nation of stockholders is appealing but, in practice, the plants' old Soviet-style managers gained control.

Sentence 2: Having a nation of stockholders would be good.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: Or maybe the behavior of eBayers can be explained only by subtler and more carefully tested theories that have not yet been devised.

Sentence 2: We would probably need more data about eBayers to predict their behavior.
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: The nation's human capital and knowledge-forms of intangible capital-are not part of the NIPA definitions of saving and investment.

Sentence 2: Intangible capital can not be defined as savings and/or investment in any situation.
Is this second sentence entailed by the first?

Answer:
it is not possible to tell