“farmland in the UK, up until the last budget, was not subject to inheritance tax. This made it popular as an investment for very rich people, which pushed the price up markedly. It’s quite tricky to precisely model the value of the tax shield, but the marginal rate[1] of inheritance tax is 40%; if you’re close enough to the Grim Reaper to be thinking seriously about estate planning, you might be willing to accept a really quite low annual rate of return in order to avoid that.
Which is what happened – in the thirty or so years since Agricultural Land Relief was brought into the tax code, the price per acre of farmland has gone up roughly fourfold, and according to credible numbers I’ve seen, there are plenty of farms which, considered as businesses, are earning a return on assets of less than 1%”
https://backofmind.substack.com/p/things-you-do-which-youd-rather-not