Yvette is a college student who lives in San Francisco and does some consulting work for extra cash. At a wage of $35 per hour, she is willing to work 4 hours per week. At $45 per hour, she is willing to work 8 hours per week. Using the midpoint method, the elasticity of Yvette’s labor supply between the wages of $35 and $45 per hour is approximately , which means that Yvette’s supply of labor over this wage range is .

Wo firms, a and b, each currently dump 50 tons of chemicals into the local river. the government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river. it costs firm a $100 for each ton of pollution that it eliminates before it reaches the river, and it costs firm b $50 for each ton of pollution that it eliminates before it reaches the river. the government gives each firm 20 pollution permits. government officials are not sure whether to allow the firms to buy or sell the pollution permits to each other. what is the total cost of reducing pollution if firms are not allowed to buy and sell pollution permits from each other? what is the total cost of reducing pollution if the firms are allowed to buy and sell permits from each other? a. $3,000; $1,500 b. $4,500; $3,500 c. $4,500; $4,000 d. $4,500; $2,500