It's worth noting that other comparable countries don't delegate law-making power to the executive in the same way the US does. For example in the UK only Parliament may make laws, the civil service can draft it but that's the limit (post-EU-exit that is, the EU is something else).

There is a concept called a statutory instrument in which the process is optimized by allowing changes to be made to law either by "laying them before" Parliament, in which case only approval or rejection is possible, not amendment. Annulling new regulations in this manner is extremely rare however. Or in some cases it's allowed for the responsible Minister or committee of MPs to make the changes directly, which in practice means they sign off on changes proposed by the civil service. This is usually only the case for very minor changes like updating thresholds, shutting down roads for construction work etc.

Despite the inability of the civil service to directly change the law, the UK is not suffering from a deficit of regulations. So there's no reason in principle it should harm productivity, unless you mean, productivity of the government itself.

It seems like an important distinction that unlike the US their government intentionally collapses if the legislature no longer supports the executive. Given two separate legislatures, the filibuster, the presidential veto , fixed terms, etc. it might just make sense for the US government to work a little differently.

As an FYI: Parliamentary governments routinely delegate regulation-making power to the particular Ministries, in exactly the same way as the USA Congress delegates it to executive agencies.

https://www.parliament.uk/about/how/laws/secondary-legislati...

Yes I mentioned SIs already. The powers are technically delegated to a minister not an agency, however, who is (almost always) an elected member of parliament.

That's not true, negative procedure SIs do not need to be approved. They can only be rejected. Most SIs are negatives, not the positives that you described.