We use our Property Management software to capture a lot of background information, but we find that the information may lag a couple of weeks from being real time. 

Fixers lag a bit which suggests to me it is mostly retail/extremely low conventional mortgage rates driving all this.   

They may also lag a day behind.

@Sam Leon I can always request verification of status in school down the road but  verifications tend to lag a little when they drop out. 

However, they generally lag a bit, so it might not be the most up to date figures. iPropertyManagement publishes Rental Vacancy Rates report every so often.

This likely changes in 20 years, but it will always lag a bit.Disorganization: A lot of people who are self-employed (realtors, contractors) are incredibly disorganized.

There are probably good credit and background check services recommended here on Bigger Pockets, but beware most may lag a week or longer with updated info.

I expect these rates to decrease a bit once the property taxes get reassessed (new construction tends to lag a bit since the govt takes time to reassess the value after the building is constructed). 

Rent increases tend to lag a couple of years behind the home value increases, from everything I've seen.And yes, in our current housing market it seems as though positive cash flow is not as easy to find as it was a few years back.

We tend to let existing tenants lag a couple of hundred dollars behind market rent... not by a lot... but with the way market rent has increased lately, just being in a lease probably means they are a couple of hundred dollars behind.