[srean]

There are many things you say here that I can totally agree with. When speed of development is a concern and costs of runtime errors are moderate enough that one can absorb them, it would be a bad idea to use Haskell (haven't used Scala so not qualified enough to comment).

Somewhere along the spectrum of increasing cost to business of runtime errors the needle switches in favor of static tyoes. This is more true when you ship applications to folks who dont necessarily know or care about the internals. Throwing runtime errors is just a bad form in those cases.

When the code is going to be deployed on infrastructure you control, there is a lot more leeway to absorb runtime errors. The choice depends on how costly the runtime errors are and how costly are the fixes. Time being part of the cost.

[sgt101]

This is a thoughtful position, the idea of quantification of costs is useful. I wonder how to propagate that back into development budgets and team behaviour.