There is a terrific shortage of rental property where DD is working as junior Doctor, to the extent that an estate agent won't even let young working people people view properties without a guarantor agreement signed in advance. And this is somewhere where junior Doctors earn quite a lot more than the average wage.
Landlords are more jumpy at the moment because of the upcoming change in legislation. It will soon be far harder to give notice to tenants. (It might actually make student lets easier, as it looks as if there will be an exemption, so if landlords have student tenants lined up for the following year, they will be able to get the students already in the property and on a fixed term tenancy to leave.)
I have just given notice to a group, who not only refused to consider a rent increase, despite paying some way below market rents, but are not house trained. Even the seasoned London estate agent was reduced to giggles as we went round the property. They knew we were coming but did not remove the beer cans off the floor or the duvets left by "visiting" friends off the sofa, and as for the damage. The agent suggested that if they stayed any longer I would not have much house left. One, who was not referenceable despite working for five years, had a guarantor - he had been trying to claim that he was so poor that he could not pay market rent when I knew full well that mummy is very rich indeed. If things get sticky, and they might still might as I don't think they yet understand how difficult it will be for them to find somewhere else and show no signs of really looking, I will write to the guarantor reminding her that she is joint and severally liable, and encourage her to engage and get them sorted.
With the legal changes I won't be able to do the same with their successors so am being much more cautious. Its fine. I got a full price offer at 30% over current rent within three viewings from a group with good jobs and references. In the current London market landlords can afford to be choosy.
(I should add that 98% or so of my tenants have been fine. But I would be mad not to factor in possibly risk.)