Final answer:
The effects of a breakout of avian flu that sickens millions of workers on the production possibilities frontier (PPF) include a reduction in labor supply, a decrease in production, and a shift inward of the PPF curve.
Step-by-step explanation:
When a breakout of avian flu sickens millions of workers, it can have significant effects on the production possibilities frontier (PPF). The PPF illustrates the maximum quantity of goods and services that an economy can produce given its resources and technology. The effects of an avian flu breakout on the PPF can include a reduction in labor supply, a decrease in production, and a shift inward of the PPF curve. This means that the economy will be producing less than its potential due to the impact of the flu on workers and productivity.