Question

14. Condoms and Teenage Sex Suppose that teenagers receive utility from sex, S, and disutility (don't like) from the risk of getting pregnant, R. All teenage couples face the following S-R constraint: R=S/100 S= 100R or where S is the frequency of sexual intercourse per month, and R is the probability of getting pregnant. The constraint above says that each additional sexual contact per month, increases the risk of pregnancy by 0.01. Assume throughout that S is a normal good andR is a normal bad for all couples. a) Don/Mel are a very sexually active couple. With S on the vertical axis, draw Don/Mel's S-R constraint, a few of their indifference curves, and their choice of S=5. b) Bill/Hill are another couple, but they are currently completely sexually inactive. On a second diagram similar to the one in part (a) illustrate Bill/Hill's choice of S=0. Currently in the common S-R constraint that they all face. Suppose that schools start handing out free condoms. While condoms reduce the risk of pregnancy for any level of sexual activity, they do not reduce it to zero. This is because (1) not all couples will take the condoms or have them available when needed; (2) not all who have them will use them (3) not all who use them do so correctly; (4) even when used correctly condoms sometimes fail. Use this additional information to answer the following questions. no teenage couple is using condoms to prevent pregnancy, and that is reflected c) What does the passing out of free condoms do to the price of sex? Explain briefly. Is it possible that Don/Mel's risk of pregnancy, R, go up? May it go down? d) What does the passing out of free condoms do to the choice of Bill/Hill? Is it possible that Bill/Hill's risk of pregnancy, R, goes up? May it go down? Explain briefly

Answer 1

) Indiperunce IC) ort Cwtve Don Mel is as follous! Sex (s) At Opigin, TCo no sex nosus prcagnanay But for an odditional sex, the risk oT pragnancy mezaones at rate of 0.01 Prubobility of Prugriancy CR) line and moving upw wrel if the 10-2 o-3 -4 0.5 P R= 5 *0 0l00.05 S=5. as upwourd sleping The 1e Cre Here thePCs are stawight uhilit'y level incruases, At 5 times Sexual intercowrse par Month, paobubili tng pat b for Bill /Hill, sho Saxunlly inachive eouple, the Cure Pe will not chauge, bacouse, the misk gehing paregnant and uhility trom ulahionship ehange Sex FvA Thun, the Te will be in Teo bac ouse the suveal ame above. Jhew is Same no sume 1on e two variabls upwevrnd +he sala tionahip tha Semaims Te meonuned mores on xes. Thu UHlity chauges dowrnisard on when Totel Paming trer eondoms will suduee the risk d pregnant, however, not nullity th choner. So, the paobabilthy Lhe presriows will he Leas than TCo ease ie 0.01 Thereforu, the fes will he is steeper han Hhe inttial pe, feo New Pe, Te

Becond Patt Don/Mel, the Rwill go doun fraseent y, sudluers lesr than 0.01) Forr Hh one 2 bacaune tRe Mish getting p-gmant Use Condoma, mosre impact d) For Bill/Hill te will ae R no if thr condoms Jue to free a becure, Oree even Sex no R = 0. betwean his couple, the value
Note: Indifference Curve (IC) moves only if the amount of total utility changes. The slope of the IC changes only when the relationship between the measured commodities changes.