We are thinking about refinancing our mortgage. Would it be better to do it now, or to wait and see if interest rates will drop even farther?

There’s no reason to rush out and refinance now. But there’s really no reason to wait, either.

Rates on 30-year, fixed-rate mortgages have been hovering around 5 percent for the past several months. That’s the lowest level in several decades.

Few economists think that interest rates are going to jump soon, but even fewer believe that they will drop farther. Inflation is low, but the jobless rate remains stubbornly high: This devilish combination should help keep rates about where they are now for the next few months.

Rates likely will begin rising in the spring or summer, though, as the economy continues to gather steam and borrowing demand from businesses and consumers alike increases. Many officials on the rate-setting Federal Reserve Board have already indicated that they’ll hike interest rates to slow borrowing if it looks like the economy starts growing too fast, and another round of energy-price hikes could force them into action sooner rather than later.

So, if you’re in the market to refinance a mortgage now, you probably should get all of the paperwork under way. There’s no pressure to get it done immediately, but keep in mind that today’s low rates could disappear within the next several months.

You recently wrote that the $8,000 tax credit for eligible first-time buyers and the $6,500 credit for repeat buyers are available to people who sign a binding contract to purchase a home by April 30, 2010. Does this mean that the transaction has to be completed by April 30, or only that the contract has to be signed by that date?

April 30 is the deadline for reaching a binding contract. The actual transaction must be completed by July 1, 2010.

Some buyers need to be more concerned about these two deadlines than others. If you’re already shopping for a home, you still have plenty of time to select a property and close the deal before the credits expire. But if you instead plan to begin house-hunting in the spring — traditionally the busiest sales time of the year, when lenders and other realty professionals get swamped and deals take longer to close — you need to keep the two dates in mind so you don’t blow the opportunity to take advantage of these valuable tax breaks.

I don’t live in New York, but I’m a huge fan of “Law and Order” and other cop shows that are based there. The “bad guys” on these shows are always sent to Rikers Island. Where is it? What is its history?

The island sits on the East River, just off the southern edge of the Bronx. It is 413 square acres, or about half the size of New York’s legendary Central Park.

The entire island originally was owned by the descendants of a Dutch settler who moved to the area in 1638. It was used as a training area for black soldiers during the Civil War. The city of New York purchased it in 1884 for $180,000 to establish a prison facility.

Today, the island’s 10 separate jails house a combined 15,000 inmates — roughly seven times the number of prisoners in Maine’s entire penal system.

A few months ago, you wrote that parents who co-sign for a child’s mortgage application can be forced to make the payments themselves if their son or daughter defaults. But what would be our financial responsibility if we gave our son and daughter-in-law some money for a down payment, rather than co-signing for their loan? Would we still be obligated to make their monthly payments if they cannot make them?

No. Parents who simply give their kids some down-payment assistance cannot be held financially responsible for future payments if the loan eventually goes into default. The lender can’t demand that the parents make the payments unless the folks also co-signed the mortgage application.