Please show me the steps in achieving the answer, -2
You want to price posters at the Poster Showcase profitably and
run an experiment to estimate the demand elasticity. You raise the
price of kitten posters by 10% but keep your dog poster prices
unchanged. After a month, kitten poster unit sales fall by 12%, but
dog posters rise by 8%. What is the difference-in-difference
estimate of demand elasticity?
a. -1.2 b. -2.0 c. -0.8 d.