Hi! Author here. This was actually my second article on wages and inflation (the first one can be found on my site - Dec 4, 2022 - Wages and Inflation). In that one I tackled the generalizability of the result, especially to the US economy. I 100% agree that for a result to hold, we need similar assumptions and conditions (basically the issue of external validity of a study). Regarding wage growth and inflation and the causality between the two, it actually has been studied quite heavily. From my previous post:
"Due to the simplicity and logical appeal of this theory [wage-price spirals], it has been heavily tested empirically. Most empirical studies to date suggest, however, that wages do not cause1 inflation. Schwerzer and Hess (2000) from the Cleveland Federal Reserve did an overview of the economic research at the time and found very little evidence supporting the idea that wages cause inflation. Only one study showed a causal impact2, while three others, and Schwerzer’s and Hess’ own work were not able to find this causality. The reason for the ambiguity in results is because inflation and wages move so closely together that attempting to separate and isolate which one causes which is not straightforward to do. Their own work focused solely on establishing the direction of causality, using what is called in economics and statistics “Granger causality”, which is a test whether the future values of one time series3 (inflation in our case) can be predicted by past values of another time series (nominal wage growth) and vice-versa. The review and analysis conducted by Schwerzer and Hess suggests that increasing wages do not cause inflation. On the contrary, evidence likely points to inflation driving increased wages."
So I would say so far the preponderance of evidence suggests there is unlikely to be causality of wage growth on inflation [in the US]. Multiple methods have shown the causal link is unlikely.
Are there circumstances in which wage growth can be the trigger of runaway inflation - I suppose there will be such conditions (how feasible/realistic they are is also a question). Have they occurred it in the US - does not appear so.
However, regarding the main issue at hand (i.e. current inflationary surge), there is even more evidence that it has not been the case, and we are nowhere near wage growth that would make us wonder about the wage-price spiral. Real wages are growing well below productivity.
Summarizing - you are 100% right that it is important to keep an eye out on external validity issues. It is also important to state the underlying assumptions (whether it is regarding the conditions of the economy or the mechanisms). It is something I am trying to get across with all of my writing and maybe could have done a better job in this particular case (although I have written a more theoretical post on the same topic, so that influenced the writing here)
"Due to the simplicity and logical appeal of this theory [wage-price spirals], it has been heavily tested empirically. Most empirical studies to date suggest, however, that wages do not cause1 inflation. Schwerzer and Hess (2000) from the Cleveland Federal Reserve did an overview of the economic research at the time and found very little evidence supporting the idea that wages cause inflation. Only one study showed a causal impact2, while three others, and Schwerzer’s and Hess’ own work were not able to find this causality. The reason for the ambiguity in results is because inflation and wages move so closely together that attempting to separate and isolate which one causes which is not straightforward to do. Their own work focused solely on establishing the direction of causality, using what is called in economics and statistics “Granger causality”, which is a test whether the future values of one time series3 (inflation in our case) can be predicted by past values of another time series (nominal wage growth) and vice-versa. The review and analysis conducted by Schwerzer and Hess suggests that increasing wages do not cause inflation. On the contrary, evidence likely points to inflation driving increased wages."
So I would say so far the preponderance of evidence suggests there is unlikely to be causality of wage growth on inflation [in the US]. Multiple methods have shown the causal link is unlikely.
Are there circumstances in which wage growth can be the trigger of runaway inflation - I suppose there will be such conditions (how feasible/realistic they are is also a question). Have they occurred it in the US - does not appear so.
However, regarding the main issue at hand (i.e. current inflationary surge), there is even more evidence that it has not been the case, and we are nowhere near wage growth that would make us wonder about the wage-price spiral. Real wages are growing well below productivity.
Summarizing - you are 100% right that it is important to keep an eye out on external validity issues. It is also important to state the underlying assumptions (whether it is regarding the conditions of the economy or the mechanisms). It is something I am trying to get across with all of my writing and maybe could have done a better job in this particular case (although I have written a more theoretical post on the same topic, so that influenced the writing here)