Social Capital has no standardized definition, so anyone can conduct a study and define “social capital” to fit however they would like it to in order to make their point. I question Putnam’s entire methodology in this specific regard, and seeing as his works on social capital are controversial in social sciences community, it would seem im not alone.
Putnam assumes that defined institutions — national organizations with local branches —are the only way for people to form communities. We’ve decentralized. It’s no longer the churches and BSA that bind us together, but other less formal institutions, like maker spaces, meetups, gym classes, etc. Perhaps they are less effective at philanthropic activities, but they still provide community. In this case, it’s not the lack of a shared identity that is robbing our nation of class mobility, but a lack of programs (federal or local) that facilitate it. For one reason or another, people stopped going to church and they stopped joining the BSA. These trends are unlikely to reverse. Now those in favor of small government are fighting its expansion to fill the vacuum these groups left behind.
No, the real problem is an attitude of “we’ve always done it this way; why change?” followed up with combative actions, when the old ways are no longer working and we have to at least try something new. The old ways may still work in Utah, but small government no longer works in states like MA, NY, CA, or any other highly urbanized community — and the trend is towards urbanization.