Where did the "Get" button go for downloading podcast episodes in iTunes?

I was wondering about the same thing earlier, just double-click the episode and it will be downloaded.

To fix it, go to control panel, then Add or Remove Programs (or Uninstall Programs). Then scroll down to find iTunes, right-click on it, and select repair.

There is no need to reinstall, or "fix" anything. The "get" button has been removed in favor of implementing podcast downloading by just double-clicking on the episode title.

Just double-click anywhere on the episode title and it will be downloaded as normal.

The "GET and GET ALL" are hidden. For me the buttons were hidden under the Date Released. clicking that will present the buttons.

Is this for all podcasts or just The Economist?

There is no podcast in the iTMS that goes by that exact name, though there is "The Economist: All audio." Maybe a podcast you used to subscribe to was discontinued on iTunes? A quick Google reveals that The Economist Audio Edition so described is a pay-for subscription podcast. Maybe that's a recent development, and why you can't get the episodes anymore.

Try searching for podcasts in iTunes by selecting the Store, entering your query, and then limiting your results to podcasts.