Inventory Up All Over

It seems like inventory is up all over across the country. People have been posting MLS data on the various blogs and it is clear that the number of houses for sale is on the increase. I wonder if some of the increase is seasonal, but I suspect not. Assuming that the summer is the "slow" season for listing houses, then presumably the spring would have been busier. This does not seem to be the case, at least at the shore, since the MLS numbers over the summer were higher than the amounts in the spring.