What are some problems facing the social security system? suggest a possible solution, and give one reason to support your solution.

The problem boils down to money, but I am assuming you are looking for the causes of the problem. 

1. Social Security was never indexed correctly to accommodate the growing life expectancy on those drawing on it. The age at which you can collect should have changed in concert with the life expectancy of the population, or the amount of the benefits should have been decreased if they wanted to keep the age at which you receive it from keeping pace with lefe expectancy. 

2. The growth in income inequality has led to vast amounts of money being earned by fewer people and the tax on social security has a limit so any income over the limit is not subject to the tax. Right now that cap is around 109k/year...so someone making 125k/year pays the same amount into social security as someone making 10 million a year. As more wealth is concentrated with fewer people, even vast increases in income and/or wealth yields little increase to the amount collected via the SS tax. 

3. Not necessarily on the scale as 1 and 2 above but fraud is also a cause of the monetary shortfall. There are those that cheat the system. Every so often you will hear stories of people getting caught in social security fraud rings where they collect either through identity theft or other criminal means. You also have people that will collect when a relative passes away. They will purposely not report the death or provide invalid SS information so they will continue to receive the deceased person's benefits long after they have died. 

As far as a solution, you are stuck with the eventuality of either decreasing benefits, raising the retirement age, or increasing the amount of taxes collected...none of which are likely to fly in Congress. Programs like SS rely on growing the base of people from which you are collecting, but at some point this does not happen. Population growth is not automatic and even with population growth, the concentration of income at the top percent of people offsets any such growth. It may be considered a very progressive/liberal thought, but eliminating the cap on income from which SS tax is collected would help. You can still keep the cap on SS benefits meaning the people at the top of the income ladder would be paying far more than they would get out of it in 10 lifetimes...but this would neutralize the income inequality impact on the system. To be honest, if there was an easy solution, we would have done it by now.