In a previous post Big Data: Don't throw the baby out with the bathwater, I made the case that in many instances, we aren't concerned with issues related to causality. "If a 'big data' ap tells me that someone is spending 14 hours each week on the treadmill, that might be a useful predictor for their health status. If all I care about is identifying people based on health status I think hrs of physical activity would provide useful info.  I might care less if the relationship is causal as lo