What Majromax said. (You're a great blogger!)

". . . proceed slowly and not make any big sudden changes." But what strikes us as a "change" in a situation will depend on which properties are in focus. For example, if this year the population of the country is P, there will be a change unless next year the population is P. On the other hand, if this year the absolute rate of change of the population is +Q people per year, there will be a change unless next year the population is P + Q (and the following year P + 2Q, etc.). If we focus on both size of population and absolute rate of change, we will have to reconcile ourselves to (what strikes us as) "change"--change in at least one of these properties. (And then, on the third hand, if this year the population is growing at n%, there will be a change unless next year the population is P * (100 + n)/100 (and the following year [P * (100 + n)/100] * [(100 + n)/100]. Etc.) Conservatism is incoherent without some underlying assumption about the relative importance of properties. The idea must be to avoid big changes in the more important properties, with correspondingly less worry about changes in the less important ones. But since we probably do not agree about the relative importance of different social properties, conservatism will not take us very far.

“[S]ocial institutions may or may not change when migration policy changes.” And social institutions may or may not change when migration policy stays the same. Now in fact social institutions will almost certainly change, in any case. The relevant questions are: how good (for productivity) are the social institutions that would follow upon the adoption of this or that immigration policy (including the retention of the old policy)? I doubt that we can have much confidence in any precise answers to these questions.

“Any change in government spending on newly-produced goods and services (G) and/or taxes (net of transfer payments, which are negative taxes) (T) is fiscal policy.” Well, keeping gov’t spending and taxes *the same* should also count as *fiscal policy*. And what about gov’t spending on things other than newly-produced goods and services—say, on land, or second-hand goods, or stocks and bonds, or its own previously-issued debt? None of that (not even the last item) seems like monetary policy! (What is the term for gov’t policy that is non-fiscal and non-monetary?)