I'm not currently doing a physics degree, but I intend to do a joint physics degree. The career options tend to be decent e.g. you can go into engineering, tech (not that you need a degree to go into most areas of tech), physics, economics (don't ask). Physics/maths graduates are also tend to go into actuarial science and quants grad schemes (or so I've heard).
As with a degree in any subject, you can also go into 600+ different careers, primarily because they don't require degrees in the first place.
If worse comes to worse and you graduated with a physics degree but wish to have the option to do a master's in economics, you can always do a postgrad conversion course in economics prior to doing a quantitative economics master's. You're very very unlikely (i.e. I don't know of a case where this is possible) to do an undergrad in economics then a conversion/master's in physics.