Friday, November 25, 2022

Correlation is Not "Causation"

All economic benefit forecasts hinge on the assumptions made about the correlation between some investment and expected outcomes. 


But few--if any-- studies actually claim a causal relationship between home broadband and economic outcomes. Generally, less direct descriptions are made. Broadband is said to have effects on economic growth rates, for example. Broadband is said to influence economic growth.  


Or faster broadband, such as 5G, is said to provide economic benefits as well as social outcomes. We might agree that broadband has “effects, influence or provide benefits of various types. 


We might agree that quality broadband tends to be associated with higher or faster economic growth. But that is correlation, not causation. Consumer purchasing of faster-speed broadband is associated with higher incomes, higher levels of education and wealth, for example. But nobody claims broadband “caused” higher income, education levels or wealth and income. They tend to be associated. 


Such correlation is often cited as “causation,” but economists rarely are so direct, though some might have made such claims. 


“High levels of broadband adoption are (arguably) causally associated with higher incomes,” says one study. Note the wording: even a correlation between broadband and higher incomes is only “casually associated.” No claim of causality is made. 


“Our analysis indicates a positive relationship between broadband expansion and economic growth,” says another study. “Although the evidence leans in the direction of a causal relationship, the data and methods do not definitively indicate that broadband caused this economic growth,” the study concludes. 


Likewise, home broadband or internet access is claimed to boost productivity, or is at least said to be correlated with such gains. The issue there is a broader difficulty measuring knowledge worker or office worker productivity, not simply the assumed impact of broadband. 


It is one matter to argue home broadband or faster broadband provides benefits. It is another matter to argue that the faster speed “causes” outcomes. Again, correlation is not “causation.” 

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