Selecting a Social Security age to balance consumption and risk Barry R. Cobb, Jeffrey S. Smith* Virginia Military Institute, Department of Economics and Business, Lexington, VA 24450, USA Abstract This article uses Monte Carlo simulation to determine the maximum consumption given retire- ment at age 62, initial wealth, risk tolerance, and Social Security take decision. Coile et al. (2002) argue for a delay, because the payment increases seven percent for each year. Focusing on maximiz- ing the expected present value of benefits may be misguided. This article shows that, conditional on retirement at age 62, initial consumption is always maximized by taking Social Security no later than age 63; it also results in the highest simulated ending wealth at death, and the lowest amount of simulated time (if any) living on just Social Security. © 2020 Academy of Financial Services. All rights reserved. Keywords: Social Security; Consumption; Monte Carlo simulation 1. Introduction Everyone is faced with several major questions in life, such as: which college to attend, who to choose as a spouse, when to have children, and of course, when to take Social Security? Unlike many of life’s other choices, the decision about when to claim Social Security is irrevocable; therefore, it is one that fills people with much uncertainty. This arti- cle will attempt to guide future retirees in their choices of when to begin receiving Social Security benefits and how much to consume throughout their retirement. Building upon the insights provided by Alderson and Betker (2017), this article uses a Monte Carlo simulation model to show that the decisions regarding when to claim Social Security and how much to consume during retirement are ultimately questions of risk tolerance. To be more specific, *Corresponding author. Tel.: +1-540-464-7542; fax: +1-540-464-7005. E-mail address: smithjs@vmi.edu (J. S. Smith) 1057-0810/20/$ – see front matter © 2020 Academy of Financial Services. All rights reserved. Financial Services Review 28 (2020) 201–221 “What level of confidence does a person require as it pertains to the possibility of exhausting their wealth before they die?” The answer to this question affects the level of consumption that a person can pursue in their retirement years, how much wealth they possess when they die, and how long they may have to live at a minimal consumption level if their savings is exhausted. Alderson and Betker (2017), in keeping with Modigliani’s (1966) theory of consumption smoothing, presume that individuals want to maintain constant real consumption across their lifetime. They asked the question, “Does a person that postpones taking Social Security get adequately compensated for doing so?” To answer this question, they calculated the proba- bility of exhausting tax-deferred savings given a person’s retirement age and the age they decide to take Social Security. This article addresses a fundamentally different, but similar question: “What is the maximum amount of real consumption a person can choose, given their risk tolerance and the age at which they take Social Security?” Monte Carlo simulation helps to reveal the maximum amount of consumption that is consistent with a person’s risk tolerance. The questions posed by Alderson and Betker (2017) and this article are different than pre- vious research. Heretofore, most research that focused on when to claim Social Security did so with the intent to maximize the expected present value of the stream of benefits. Coile, Diamond, Gruber, and Jousten (2002) use simulations to show the optimal delay for both individuals and one-earner married couples using both the expected present value under financial calculations and a utility maximization model. They find that it is optimal to post- pone, with delay times that ranged from months to years, in a large number of circumstan- ces. Docking, Fortin, and Michelson (2012) solve for the optimal retirement age given gender and race for single individuals. They find the decision is invariant to race and gender; individuals should either retire at age 64 if they retire early, or they should retire at age 67. Similarly, Shoven and Slavov (2014a) calculate expected present value of benefits for a number of different situations and find that individuals who expected to live according to the average mortality tables should delay taking Social Security past their full retirement age unless the real interest rate is four percent (or higher). Shoven and Slavov (2014b) show that the benefit from delaying Social Security has risen over time, with someone born in 1951 (close to the baseline for this article) gaining 12.7% if they delay claiming until age 69. There is lots of evidence to suggest delaying receipt of Social Security; the popular press would summarize by saying, “wait as long as you can.” Munnell and Chen (2015) report that, in 2013, after adjusting for growing changes in the size of Social Security cohorts, 36% of men who claim Social Security benefits are aged 62. Shoven, Slavov, and Wise (2018) conduct a survey to assess people’s attitudes pertaining to their decision to claim Social Security. Seventy seven percent are happy with their decision to claim at age 62, while 90% are happy with their decision to claim at the full retirement age. The main reason cited for claiming before the full retirement age is a need for the money, and 23% of respondents state they use savings to finance the gap between retirement expenditures and Social Security income (61% stated they relied upon an employer-spon- sored pension). This article aims to guide the decision regarding when to collect Social Security, as well as how much to spend during retirement, given an individual’s risk toler- ance for failure. Here it is important to stress the definition of failure. Failure is defined as 202 B.R. Cobb, J.S. Smith / Financial Services Review 28 (2020) 201–221 fully exhausting the initial stock of wealth such that the individual must live only on their Social Security benefits. According to a report by the U.S. Government Accountability Office (GAO) (2019), 48% of households aged 55 and over have no retirement savings, but may have a defined benefit plan. Twenty nine percent of households have neither. The GAO gathered this information from the 2016 Survey of Consumer Finances. Thus, in this model, failure is defined in accordance with the state of wealth accumulation that is consistent with almost a third of American households, and possibly as many as 50% of households. 2. The model The basic decision is a function of gender, wealth, annual level of consumption, the age at which an individual begins collecting Social Security, the portfolio’s asset allocation, and the annual return an asset earns. Gender is not a factor in the model; results are simulated for males and females separately. Thus, gender affects the probability of death. A retiree’s wealth, Wt, is modeled in year t as Wt ¼ Wt�1 þ Pt � Ctð Þ � 1þ aEt þ 1� að ÞBtð Þ (1) where Pt is the Social Security payment in year t; Ct is the consumption in year t; a is the percentage invested in stocks, with stock (equity) and bond returns denoted by Et and Bt, respectively. Fig. 1 depicts the structure of the simulation model utilized to evaluate the retirement portfolio that includes Social Security payments. The elements of the model and the components of (Eq. 1) are described in the remainder of this section. Fig. 1. Structure of the retirement portfolio model. B.R. Cobb, J.S. Smith / Financial Services Review 28 (2020) 201–221 203 2.1. Stochastic assumptions The retiree divides wealth among investments in stocks and bonds. Total returns from the S&P 500 are used to model stock returns, and total returns on 10-year Treasury Bonds repre- sent the bond returns. Both series range from 1928 to 2018 and were retrieved from Professor Aswath Damodaran’s website (Damodaran, 2019). The article uses this site due to the long history and the singular source. These data span the Great Depression, several wars including World War II, and several extremely volatile periods for stocks. Additionally, accurate total return series for bonds are hard to access, especially across such a long history. Professor Damodaran calculates the price return for a 10-year Treasury Bond and adds that to the coupon received for the 10-year Treasury Bond. Therefore, these data give us average returns for both series and good correlation between the two. Random variables are established by creating probability distributions for annual stock and bond returns, and these returns are correlated within each year. Stock returns in each year are modeled as normally distributed with a mean of 11.5% and a standard deviation of 19.6%. Bond returns are normally distributed with a mean of 5.2 percent and a standard deviation of 7.7 percent. Returns are uncorrelated across years, but the stock and bond returns within each year are modeled with a correlation coefficient of –0.0276. Alderson and Betker (2017) use a bootstrapping approach and randomly sample an actual observation of investment returns to calculate the simulated returns for a given year (e.g., for year one their simulation might randomly select the historical return from 2010, in which case their model will use the total return for stock and bonds from 2010). In contrast, the portfolio model in this study defines the distributional parameters and then uses Monte Carlo simulation to sample both stock and bond total returns. Inflation is estimated using the difference between the yield to maturities for Treasury Inflation-Protected Securities (TIPS) and the yield to maturity for similarly dated Treasury securities matched for maturity dates from 2019 through 2029, with the smallest one-year difference being 1.705 percentage points and the largest being 1.959 percentage points. These inflation estimates from 2019 through 2029 are used to develop a normally distributed variable with a mean (1.88 percent) and standard deviation (0.277 percent) that follows from the projected inflation rate across these 11 years. Correlation between inflation and bond and stock returns is estimated by calculating the correlation between the Consumer Price Index (CPI) and bond and stock returns across the entire time period of the sample. This inflation rate is used to maintain constant real consumption for an individual, while also adjusting the level of Social Security benefits that will be paid in the future. On each simulation trial, a random number of years (L) until death is selected. This ran- dom variable is created using current Social Security life span assumptions. This is accom- plished by running 10,000 simulation trials from the Actuarial Life Table (Social Security Administration, 2018) and then compiling results for conditional remaining life span given that an individual (male or female, as appropriate) obtains age 62. At the age of 62, a female is projected to live 2.82 years longer than a male. The average male life expectancy in the model is 19.44 years, which would suggest that a male that retires at age 62 will live to be approximately 81.44 years old, while a female will live to be approximately 84.26 years old after an average life expectancy of 22.26 years. The oldest person in any simulation was 204 B.R. Cobb, J.S. Smith / Financial Services Review 28 (2020) 201–221 108. These numbers are in line with, but longer than, the Cohort Life Expectancy published by the Social Security Administration in Table 5.A5 of the 2019 Annual Report of the Board of Trustees of the Old Age and Survivors Insurance and Federal Disability Insurance Trust Funds (2019). Using calendar year 1955 (one year before the latest birth year of 1956), males are expected to live an additional 13.1 years past 65 (78.1 years), while females are expected to live 16.7 years past 65 (81.7 years). 2.2. Social security benefit payments The retirement portfolio model assumes that an individual retires at the earliest opportunity to claim Social Security, which is currently age 62. Unlike in Alderson and Betker (2017), who use the online Social Security benefits estimator, the model calculates the Social Security benefit using the process in Appendix D from the Annual Statistical Supplement to the Social Security Bulletin for 2018, released May 2019 (Social Security Administration, 2019). The model assumes that an individual who begins working at age 18 and works until age 62 earns at least the maximum amount of income that is subject to Social Security tax in the highest 35 years of their working life. The initial benefit SA is then estimated to coincide with the age, A, at which they start to collect Social Security. The benefit is adjusted for stochastic inflation, It, in each year so that the Social Security payment Pt in each year is determined as Pt ¼ R � SA � Yt�1 u¼1 1 þ Iuð Þ (2) where R is an indicator variable that is equal to 1 if t