Owner agrees to rent Tenant her lake house for the summer for $4,000. How much income does Owner realize if she agrees to charge only $1,000 if Tenant makes $3,000 worth of improvements to the house? Is there a difference in result to Owner in Problem A if Tenant effects exactly the same improvements but does all the labor himself and incurs a total cost of only $500? Are there any tax consequences to Tenant in Problem B?