[noogle]

The logical conclusion is to move to the US, then. But seriously, the software industry concentrates in the US. The high salary represents (in part) this concentration rather than something about the US itself. Thus, it makes sense that companies are not looking outward - employees that are worth this kind of salary have already moved to the US. Similar to how other industries chose other places to concentrate. Any "market" of numerous agents requires an agreed-upon "marketplace" - not just geographically, but also legally.