A 2 x 4 costing over $6 is unreal. I would hate to be building a house. Fortunately the hardwood (oak, walnut, cherry) has not gone up so much.
It has to impact new housing and thus housing costs. However I believe they keep shifting the weights to have minimal official inflation.
Do you know why the mills haven’t increased production? Is it the supply of trees? Covid impacting manufacturing? Ammo is another thing that is sky high. I suspect ammo is not in the CPI though. :)
Production has increased somewhat in the last quarter in lumber. What I hear from the sawmills is they can not hire enough people. The same issue companies are having everywhere in the US. People do not want to do physical labor type jobs.
There is no shortage of timber other than specific areas like southern OR(I5 area) and the Black Hills of SD. There is plenty of timber in other areas. There are new mills being built primarily in AL & MS.
OSB production has been affected recently by the supply of the resin/glue used to bond the panel together. Most was being made down in TX/LA and was curtailed by the weather/ice/snow storm in late winter.
Initially, production was curtailed by covid last spring. Several mills were shut down leading to shortages of Southern Yellow Pine lumber used primarily for pressure treating.
It has greatly increased the price of a new single family home. Somewhere in the $25K range.
It is not just lumber, plywood and osb that have gone up in price. Romex wire has doubled with the price of copper. Steel(plates, nails, screws) are up 30% or more.
In addition, plumbers, electricians, roofers and other tradesmen are so busy they have raised their prices/job and hourly labor rates because they can. This is because people are spending a lot more money on their homes than they formerly did. Hot tubs, pools, additions, bath & kitchen remodels have all increased because people are not taking vacations, going to dinner, etc.