The second paper shown above is firewalled.
The first paper shown above was presented at ICPC, which has a history of bias in reviewing, and typically only assigns one or two reviewers in any case.
Which makes it not surprising that the paper itself doesn't really prove anything, except that the authors themselves are good at creating dissimilar situations.
Subjects had to modify existing systems, which were provided by the experimenters.
The experimenters deliberately removed any semblance of anything that might hint at types (comments, variable names, etc.) and did who the fuck knows what else to the dynamically typed code to make it difficult to work with.
They also provided their own IDE and full environment which the participants had to use.
Now, of course, we've all seen the graphs which show that for simple problems, dynamic is better, and there's a crossover point, and, of course Cooley's experiment is on the far left of that graph, so it certainly doesn't prove that strict static typing isn't better for large programs, but it's at least honest in its approach and results, using self-selected working practitioners (and there was never any shortage of working practioners swearing by how much better VHDL is).
https://danluu.com/verilog-vs-vhdl/