THE comparison of renting versus buying examined the major costs of both options, using averages and estimates from several sources.

For buyers, the assumptions included:

A down payment of 20 percent of a house's value.

A mortgage interest rate of 5.35 percent. That is roughly the initial rate on a jumbo mortgage with no points and a fixed rate for the first five years, according to BankRate.com.

An annual property tax rate equal to 1.25 percent of a house's purchase value, a rate that is typical throughout much of the Northeast and California.

Annual spending on repairs and renovations equal to 1 percent of the house's purchase value, based on government data about household spending.

A home insurance policy that annually costs 0.3 percent of the house's purchase value, based on data collected by the Insurance Information Institute.

Transaction costs equal to 4 percent of a house's value.

A marginal tax rate - for federal, state and local taxes combined - of 35 percent.

For renters, the calculations were based on:

A comparison of house prices and rents in 54 metropolitan areas, provided by Economy.com.

Annual rent increases of 3.5 percent.

Renters' insurance equal to roughly $15 to $20 a month, depending on the house's value.

Annual, after-tax return of 4 percent on the money that would otherwise have been spent on a down payment. This is the same discount rate used to compare money spent in 2005 with money spent in future years. DAVID LEONHARDT