Readers suggested a look at rents and home prices as a topic. "Does anyone have linkable data that shows that historically that median income can afford median home price, and also, that median home payment equals median rent?"

"I know both of these mantras are just 'common sense,' but I was wondering if there was a graph out there anywhere, or a linkable source with that data."

"The reason I am asking, a few family members have told me that I am crazy, and that those ratios never existed. Rent has never covered the mortgage on homes… They drank too much kool aid, and I need to help them on the road to recovery."

A reply. "If you Google the US Census Bureau website you can see median income/ home prices for all states and metro areas. I checked Palm Beach County awhile back. I believe on 1/1/00 the median income was about $45K and the median price was $135K. I think we will see a ratio of 3:1 again as our economy doesn’t warrant $400K median prices."

Another, "You can look at a chart that shows the ratio of home prices to rent. As you can see the ratio has never been so high as far as the chart tracks, back to the 70’s."

"This site has a price to earnings graph."

Another wants more graphs, "Weekend topic: Favorite statistics, charts & graphs!!!"

One said, "I believe the NAR Affordability Index shows how much median house the median income buyer can afford on a nationwide basis. As you would expect, it is at a record low now."

A look back at the Economist, "The most compelling evidence that home prices are over-valued in many countries is the diverging relationship between house prices and rents. Just as the price of a share should equal the discounted present value of future dividends, so the price of a house should reflect the future benefits of ownership, either as rental income for an investor or the rent saved by an owner-occupier."

"Calculations by The Economist show that house prices have hit record levels in relation to rents in America, Britain, Australia, New Zealand, France, Spain, the Netherlands, Ireland and Belgium. This suggests that homes are even more over-valued than at previous peaks, from which prices typically fell in real terms. House prices are also at record levels in relation to incomes in these nine countries."

The International Herald Tribune. "To buy or not to buy? (It) is being performed more frequently at kitchen tables and real estate offices around the world. That is because the math associated with the rent-versus-buy debate has grown a lot fuzzier lately, and the numbers threaten to swamp long-held convictions about the value of buying property."

"Measured by cash flow, the cost of renting seems cheaper than buying: Even without the need to scrape together a down payment or pay closing costs, the monthly outlays of not only the mortgage payment but also local taxes, insurance, utilities and maintenance in many markets have actually tilted the balance toward renting rather than buying."

"With house prices softening in many markets but not yet hitting bottom, and with higher tax assessments lifting the cost of ownership beyond more households' ability to pay, more people are deciding to rent - at least until market conditions improve."

"Noel Whittaker, a joint managing director of a financial services company near Brisbane, Australia, cited the example of a property that costs $300,000 and which can be rented for $300 a week. 'If you rent it, the total cost is $15,600 a year,' he said. 'But, if you buy it, you will be up for at least $24,500 a year when you take interest rates and maintenance into account.' That's nearly $9,000 a year in favor of the renter."

"A couple that rented for two years 'will have an extra $18,000 to use as a deposit when they eventually do buy,' he said."