When enthusiasts talk about private accounts as part of Social Security, they’re selling a dream. It’s as easy as your company 401(k), they say.

Part of the Social Security tax you currently pay would be deposited into a private investment account. You could choose whether to put it into stocks or bonds.

Your Social Security benefits would be reduced. But by the time you retired, your investment account would supposedly bring you out ahead.

There’s a big piece missing from this fairy tale. No one talks about how the accounts would actually be handled.

What about the practical stuff? What will it cost to sign people up for personal accounts, keep track of their choices, report their gains or losses and fix mistakes? Those chores are more complex than you think. I doubt very much they could even be done.

But you might ask if private companies can run 401(k)s, why can’t those same systems be transferred to private Social Security accounts?

Sorry there’s a huge difference between the two.

A 401(k) serves a single employer. It’s handled through electronic payroll deductions. The average account is usually of a substantial size. At the largest 401(k) the federal government’s plan an average of $4,900 generally gets added to each employee’s account per year.

Compare this with what might happen if Social Security started private accounts. It might start with 154 million people and add 5 million names a year. It’s dealing with more than 6.5 million employers, almost all of them small. More than 80 percent of them report wages on paper forms rather than electronically.

The Social Security rolls include part-timers, seasonal workers, non-English speakers, tens of millions of people who know zip about investing and at least 10 million who don’t even have a bank account.

Record-keeping nightmare

Let’s say 2 percent of your earnings went into private accounts, as many plans propose. In that case, about half of all workers would contribute $400 or less per year, said Dallas Salisbury, head of the Employee Benefit Research Institute.

All those accounts large or small need tracking, tallying and telephone service at an overhead cost of maybe $10 a call.

In a single column, I can’t begin to mention all the additional administration problems the government would face.

Here are just a few for starts:

-Choice. Most people expect a private Social Security account to look like a 401(k). They won’t want just one investment fund. But by adding even a single choice, you add a vast amount of complexity and cost.

-Participation. How would the government enroll every worker in the United States?

Imagine the cost of just finding them all. More likely, accounts would be voluntary. Employers would have to keep track of which employees joined and when. Do companies really want to do that?

-Investment timing. When would your Social Security money actually be deposited into your personal account? Currently companies send your payroll taxes to the government at various times throughout the year. But they report your actual wages only once, at tax time. As a result, it takes seven to 22 months for your earnings to be posted to your account.

That normally doesn’t matter because it doesn’t affect any Social Security benefit you get. But are you willing to wait up to 22 months for money to be invested in a personal account?

Probably not. For faster crediting, employers and the self-employed would have to report to the government more often.

-Fixing mistakes. Company wage reports are littered with small mistakes.

Social Security normally ignores discrepancies of $830 or less because they’d probably make no difference to the size of your benefit.

But if it’s your own investment money, would you be willing to lose $830? No way. Social Security might have to contact 1 million employers or more to reconcile reports to the penny. Think of the letters, phone calls, paperwork, staff and arguments.

-Compliance. What if employers go out of business and don’t forward payroll taxes? Today, you get your full benefit as long as you can show you worked. With private accounts, however, that money could be lost.

Syndicated columnist Jane Bryant Quinn can be reached in care of the Washington Post Writers Group, 1150 15th St., Washington D.C. 20071-9200.