Note that if you Google around, there used to be some pretty good guides to how to get into Econ PhD programs out there. For example, this is good and links to some other good resources: https://chrisblattman.com/about/contact/gradschool/
[My views only, not my past or present employers']
My knowledge is out of date but I thought a lot about this about 8-10 years ago when I strongly considered getting a PhD in economics and worked as an economics research assistant at the Brookings Institution. All of the below should be caveated w/ 'as of 8-10 years ago.'
In general, +1 to dmolling's comment.
As of then, the LSE Masters in Econometrics and Mathematical Economics seemed to stand out as by far the best Econ Masters program if you wanted to go on to a PhD. Note that LSE also has other Masters in Economics programs that are more geared towards being a terminal masters and going on to work in policy as opposed to getting a PhD.
Agree with dmolling that US Masters in Economics are generally not seen as good feeders for PhD programs. Seen as low status among academic economists and geared towards getting a policy job immediately as opposed to getting a PhD. It's possible another exception is the MPAID program at Harvard, which I think makes you take most of the first year curriculum for econ PhD students (or at least used to). Make sure I'm right about this before applying.
The main other options are Masters in Statistics, applied math, or other quantitative areas. I don't know how these compare to the LSE Econometrics program but top math/stats programs probably beat US masters in econ programs. I'd guess Computer Science is also becoming a more popular background.
In general, I think the main things econ PhD programs judge you on are: 1) how many math/stats courses you've taken, how hard they were, and how well you did; 2) recommendations form top economists that the people on the admissions committee know and trust.
I was always told that a top priority was taking (at least) linear algebra, real analysis, and a couple semesters of statistics. Hopefully differential equations, too, and ideally a bunch more math than that. My guess is that taking courses like these and excelling in them is more important than whether or not you come out with a particular degree so, as dmolling says, you could just take them w/o being enrolled in a grad program. Heuristic I've gotten is that if you don't get an A in real analysis, you're probably not a good candidate for a top 6 econ program (but getting an A in real analysis is far from a guarantee; most people at those programs will have taken a lot more math than that).
General advice is that you should ask a Masters program for a list of where alums of the last several years went after finishing. For an econ Masters, if few of them went on to PhD programs you'd be happy at, assume the degree won't help your admissions prospects much.
Good point about CS - I should have mentioned that in my post. A lot of economists are starting to dip into machine learning and do some heavy computational stuff where CS background is very useful. Also recommend everything else Howie said as well.
Another point for masters programs, especially for econ masters, is to see if they'll let you take PhD level courses in your second year. If you're very confident in your ability to take a PhD level course year 2 and you do well in it that would greatly increase your odds of getting into a top 6 program (particularly intro PhD microeconomics theory). Doing badly in a PhD level course decreases the odds, of course, so that's a risky path.
+1 on taking PhD level economics courses (especially intro micro theory) and doing well on them. Not sure how much it matters where you take those courses but I'd guess high-ranked econ programs would place more weight on courses taken at schools where they expect the PhD courses to be equally challenging.
Quantitative masters are definitely a good path.
I believe the best options are:
1) Master's in statistics. If you don't have a quantitative degree from undergrad, getting into a competitive statistics program may be difficult, though. Most good programs expect at least a semester of linear algebra, multiple calculus courses, and some statistics. But, there are exceptions. The skill overlap between economists and statisticians is pretty large and admission committees love to see applicants with strong stats chops. If you cannot get into a statistics program due to lack of mathematics background I'm a little less confident in any other masters program recommendations.
2) Master's in economics in Europe from a good school. A masters from LSE or some other equally good school in Europe is a great signal and is probably as good an option as a statistics masters in the US . I believe the mathematics requirements are little less stringent here, but this may vary from program to program.
3) Any other quantitative masters program that teaches you linear algebra, calculus, and some statistics. This is if you can't get into a statistics or European econ program. I don't have particularly insight about good programs in this category, but look for programs with good research opportunities (especially if you can do research with an economic bent) so you can form relationships with professors and get a good recommendation letter.
An masters degree in economics in the US could fall into this category, but careful. My impression from talking to many PhD economists, including some that have been on admission committees for grad programs, is that an economics masters in the US is viewed as something someone gets because they couldn't get into a PhD program (and is thus low status). They're generally less rigorous than a statistics degree. There are exceptions, of course, and if you blow away faculty in your masters program with your talent and hard work you'd still likely get into a good PhD program. There are massive differences in quality across schools when in comes to their econ masters programs so research carefully and email current students if you take this route.
Possible better option than the above: get a research job and take math classes while working in your free time. Specifically, take linear algebra, calculus, real analysis (plus any prerequisites), and mathematical statistics. Differential equations is also helpful. Your grades in these math classes are extremely important to your admission probability for any economics program - probably the single most important part of your application.
Background: I worked as a research assistant for the Federal Reserve after undergrad and applied and was accepted to several mid-tier (roughly rank 15-40) PhD programs before eventually deciding I didn't want to do a PhD. I took a few math classes while working at the Fed (they paid for me to take them - a great deal).
Previously: What type of Master's is best for AI policy work?
Pursuing a PhD in Economics is one of 80,000 Hours recommended career paths (a).
It also might be a free lunch (a). (That article is a little dated, but recent correspondence with the author leads me to believe that Caplan still thinks that an Economics PhD is a good deal, for some people & some career goals.)
Entry into good Econ PhD programs is very competitive. It's especially daunting to consider if, like me, you don't have a quantitative undergraduate degree.
I've heard that getting a quantitative Master's is a good way to boost one's PhD applications. But there are a lot of Master's programs out there, and presumably some are better than others for going on to an Econ PhD.
So, does anyone have thoughts on which specific Master's programs are best-tailored for applying to competitive Econ PhD programs upon completion?
This might not apply to everyone, but one of the most neglected criteria for Master and PhD programmes generally is whether to do them in the U.S. or in Europe.
The difference is the length of the programme. In the UK for instance, many Master's programme are often 1 year and PhDs are 3 years. One can sometimes go straight into a PhD from undergraduate.
In contrast, US PhDs are usually 5 years. For people who want to go into academia a longer PhD might make sense, but perhaps for others shorter European style graduate study might make more sense.