What is the former Treasury Secretary talking about?

Larry Summers is a smart guy but his comments today on the US dollar don't make sense.

Household net worth in the US is around $90 trillion. Add in all the domestic corporate wealth and the value of all the property and assets that various US governments own and it's much higher.

Meanwhile, total public and private debt owed to non-residents is around $20 trillion.

A rise in the US dollar at this point isn't necessarily the greatest thing for US workers and businesses, but it certainly doesn't make America poorer.