There's a little-known paper published a few years ago called "An experiment About Static and Dynamic Type Systems: Doubts About the Positive Impact of Static Type Systems on Development Time".
Go read the paper, it's short. But since I know you're lazy, I'll give a brief overview of the experimental setup and its results in my own biased words. The authors made a programming language and IDE and had two versions of it: one with static typing and one with dynamic typing. They took a group of students and separated them into dynamic/static groups and trained them respectively -- the training for the static version took a little longer since they had to cover the type system. Then they were asked to implement a scanner and parser.
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