Module 5 will be a review session and Exam #1 over modules 1 through 4. 
You should turn in your first issue-paper when you take exam #1. 
The syllabus link on the course cover page has guidance for taking exam #1 and for writing issue-papers.
Closely follow the guidance in the "How to Prepare for Exams and Issue-papers" link in the red Need-to-know menu of your Syllabus.

9.2 Explain why positive externalities lead to inefficient underproduction and how public provision, subsidies, vouchers, and patents can be used to achieve a more efficient outcome.

A.  External benefits are benefits that are received by others than the consumer of a good or service.  Marginal social benefit equals marginal private benefit plus marginal external benefit.
B.  External benefits from education arise because better educated people are better citizens, commit fewer crimes, and support social activities.
C.  External benefits from research arise because once someone has worked out a basic idea, other can copy.
D.  To enable the efficient amount of education and innovation to take place, we make public choices through governments to modify the market outcome.
E.  Vouchers or subsidies to private schools or the provision of public education below cost can achieve an efficient provision of education.
F.  Patents and copyrights create intellectual property rights and increase the incentive to innovate.  But they do so by creating a temporary monopoly, the cost of which must be balanced against the benefit of more inventive activity.

9.2 Explain why positive externalities lead to inefficient underproduction and how public provision, subsidies, vouchers, and patents can be used to achieve a more efficient outcome.

A.  External benefits are benefits that are received by others than the consumer of a good or service.  Marginal social benefit equals marginal private benefit plus marginal external benefit.
B.  External benefits from education arise because better educated people are better citizens, commit fewer crimes, and support social activities.
C.  External benefits from research arise because once someone has worked out a basic idea, other can copy.
D.  To enable the efficient amount of education and innovation to take place, we make public choices through governments to modify the market outcome.
E.  Vouchers or subsidies to private schools or the provision of public education below cost can achieve an efficient provision of education.
F.  Patents and copyrights create intellectual property rights and increase the incentive to innovate.  But they do so by creating a temporary monopoly, the cost of which must be balanced against the benefit of more inventive activity.

Take the optional post-study bonus point quizzes on Externalities on Saturday following Module 4.

Expect to review for and take Exam #1 during Module 5.