I agree that studies of the form, "How long does it take to implement some app A in language X" are asking the wrong question. I thought we all knew and agreed

I agree that studies of the form, "How long does it take to implement some app A in language X" are asking the wrong question. I thought we all knew and agreed that the difficult part of most applications is maintenance. How does static or non-static affect a new hire's ability to get up to speed and support an app? How does it affect long-term maintenance, refactoring, adding features, and fixing bugs? I'm not entirely sure how to answer that question, but I'm not convinced that controlled studies will point to an answer. It might be interesting to look at corporate metadata and try to find how how much companies spend over the lifecycle of an application on the whole development and maintenance of a project. See if you can find projects with enough similarities to warrant a comparison and compare a Java app with a Python app. Probably impossible, honestly. I don't have a strong opinion on the matter. In my experience, th e design and leadership of a project have a far bigger impact on the ease of development and maintenance than the type system. I've seen very large but very elegant C# programs that were a pleasure to work on and maintain. I've seen Python web systems that are an absolute nightmare to work on and reason about. Probably most people here have experiences going both ways with different type systems. I blame the developer for god-awful messes and praise the developer when I see clean, sensible code. I never blame the language. Except for JavaScript. I will always blame JavaScript. Hell, JavaScript is probably what's really causing global warming. In general, a clear head and some discipline count more for code quality than any type system, and the lack of either definitely does more damage than any type system can. But I'd go along with the idea that statically typed languages force more discipline on younger developers who haven't yet got the experience to even know what clear-headed ness even means. Working in C# was a great experience for me coming from a self taught Python background, no question about it. It also improved and helped me structure my Python code, and becoming better at designing good Python code in turn helped me write better C#. There can be a virtuous cycle in working with different languages and type systems.