Household Saving and Investment Decisions参考.ppt

Chapter 5: Household Saving and Investment Decisions * Chapter 5 Contents 5.1 A Life-Cycle Model of Savings 5.2 Taking Account of Social Security 5.3 Deferring Taxes through Voluntary Retirement Plans 5.4 Should you Invest in a Professional Degree? 5.5 Should you Buy or Rent? Copyright ? Prentice Hall Inc. 2000. Author: Nick Bagley, bdellaSoft, Inc. E.g： How much to save for retirement Whether to get a professional degree Whether to buy or rent an apartment * 5.1 A Life-Cycle Model of Saving Assume that you are currently 35 years old, expect to retire in 30 years at 65, and then live for 15 more years until 80 Your real labor income is $30,000/year until age 65 Interest rates exceed inflation by 3%/ year Fig. 5.1 Salary, Consumption, and Saving over the Life Cycle Fig.5.2 Human Capital, Retirement Assets, and Total Wealth over the Life Cycle 跨期预算约束 人力资本 未来劳动收入的现值（截止退休） 永久性收入 现值等于人力资本的不变收入或消费水平（直到去世） How Much Should I Save and Consume? Consider two approaches: Target replacement rate of pre-retirement income Maintain the same level of consumption spending 为退休的储蓄 例：王二今年30岁，计划在65岁退休，预计自己能活到80岁。他的薪水为每年10万元，而且打算在接下来的50年里保持实际消费支出水平不变。不考虑税收、不存在实际劳动收入增长的前提下（名义劳动收入刚好抵消通胀），如果实际利率为3%，请问王二的人力资本价值为多少？永久性收入呢？ 先按照年金现值计算方法得到人力资本为： 永久性收入为： =PV(3%,35,100000,0)=2,148,722 =PMT(3%,50,2148722,0)=83,511 为退休的储蓄 预期寿命80岁 实际利率 65岁时的财富 每月养老金 12％ 507,073 6,085 10% 302,146 3,274 8% 184,249 1,761 Intertemporal budget constraint跨期预算约束 C=年消费金额（保持与退休前相同） i = 利率 R = 距离退休年数 T = 余生年数 Y =薪水收入 W0= 初始财富 B = 遗产 如果王二还面临强制性的社保缴纳，比如每年交5000，假设同样的利率，那么他个人的储蓄和退休时每期的收入是多少？ What’s the benefits? 退休金体系与人口压力 现收现付制（pay-as-you-go）与累积制 高福利下的欧洲与做实个人账户的我国 5.2 Taking Account of Social Security 买房还是租房? 租房每个月2500元 买房总价100万元 假定你的目标是以最低的成本现值给自己提供住房，假定扣除通货膨胀后的每年实际折现率为3%（房租和房价的真实增长率） Q：买or租？ 5.4 Should You Buy or Rent? 买房和租房的现值成本 不考虑维护费用和物业税等，买房的现值成本即为100万元 租房的现值成本为：=PV(0.25%,600,2500,0)，其中实际利率为3%，月0.25%。求得租房的现值成本为78万左右 因此，租房更合算 注意，这里的租金费用高低直接影响结论 售租比（房价/租