Arin, Barbara, and Cori are 30-year-old single friends who work at the same company, and each will earn $60,000 in 2018. They each have $5,500 in pre-tax dollars to invest, and are discussing their plans for saving this money. Arin plans to save $5,500 in a traditional IRA, and invest the money in a stock market index fund. Barbara plans to pay taxes on the $5,500, then save the remaining amount in a Roth IRA, also investing the money in the same stock market index fund as Arin. Finally, Cori will also pay taxes on the $5,500, and then invest this money directly in the stock market index fund, outside of any retirement account. The expected return of the fund in all three cases is 8% per year.

Discuss the advantages and disadvantages of each strategy.