And it's more than just looking at more data. It's also about understanding the data. Example: immigration from a poor country to a rich country can lower wages in the rich country while also increasing total prosperity. As to whether or not it absolutely does lower wages, it's complicated and depends on lots of factors.

In general I fall on the side that wage and mobility issues of the last several decades are a product of poor monetary policy and regulation. Growth in aggregate demand has been weak because the Fed has been keeping it subdued. Regarding regulations, here's but one example: tons of bargaining power for laborers is lost due to the vast healthcare regulations that make it so that laborers are afraid of losing their healthcare if their current labor is disrupted. It's the traumatized worker.