What does a centrally planned economy oppose that a market economy encourages

Unlike a market economy — in which private citizens and business owners make production decisions — a centrally planned economy controls what is produced and the distribution and use of resources. State-owned enterprises undertake the production of goods and services.

porter is writing economic history because he is focusing on the cost of developing vaccines.

well that depends on how deep the hole is. you'd first go through te crust of the earth, then the upper mantle, then the lower mantle then the outer core, then the inner cor then you'd be stuck in the core to melt.