left overs = les restes (exp repas)

A widespread tendency/ on the part of the Americans / to spend /rather than to save does not account entirely = n'est pas entierement responsable

Your house would have appreciated/at double the rate/ of your personal income

A lot of people have come to rely on the appreciation of such assets as a substitute for the practice of saving out of wage income

Both of these institutions are authorized to make loans

Freddie Mac bought mortgages already written by lenders, pooled them and sold them as MBS on the open market.

The only thing you can plan for is higher rates and higher payments

Planning for them to go down does not make sense

Risk is the possibility that cash flows can be variable

Not all income is equally disposable

They had fallen 8 percent by 2008

They were down from the 2006 peak

an adjustable rate mortgage