Polycarbonate: Correlation
Prices it moves with, and why
Polycarbonate is made from bisphenol A, mostly by reaction with phosgene or diphenyl carbonate, so phenol, acetone and chlorine costs feed its price. Its clarity and toughness suit glazing, car lights, electronics and medical parts.
Proxy US PPI: thermoplastic resins and plastics materials index (BLS base period) · monthly, Jan 2006 to Sep 2026There is no free public price for polycarbonate itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item.
What its price moves with
Selected linkPolycarbonate and Bisphenol A
Monthly changes 0.38 weak correlation 12-month changes 0.73 strong correlation Last 5 years 0.09 monthly changes Lead or lag none No clear lead or lag Price function, Jan 2006 to Sep 2026 Polycarbonate ≈ 6.37 × (Bisphenol A)0.69 R² 0.79 On this fit, a 10% higher bisphenol a price goes with a 6.8% higher polycarbonate price over the long run. Units: index (BLS base period) and index (BLS base period).Chart: Polycarbonate and Bisphenol A prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Polycarbonate price against Bisphenol A price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Bisphenol A makes up most of the polymer, so polycarbonate is priced as a margin over BPA. The cyclic intermediates proxy moves with the resin proxy at 0.38 monthly and 0.73 yearly.
weak co-movement month to month · 249 months Show chartsThe phosgene route uses chlorine and carbon monoxide, and its salt by-product is often recycled to chlor-alkali plants. The alkalies index moves with the resin proxy at only 0.08 monthly and 0.08 yearly, as that index also covers caustic soda and soda ash.
little or none co-movement month to month · 249 months Show chartsAcrylic sheet competes with polycarbonate in glazing, signs and light covers; acrylic is clearer, polycarbonate tougher. They share the same proxy index here, so no separate statistics are shown. Buyers switch where specifications allow.
Not enough overlapping price history to measure.LED lamps and fittings use polycarbonate lenses and diffusers. The lighting fixtures index barely moves with the resin proxy, 0.02 monthly, because fittings prices depend mostly on electronics and labour.
little or none co-movement month to month · 249 months Show chartsOil sets the cost of the benzene and propylene behind BPA. Brent moves with the resin proxy at 0.24 monthly and 0.72 yearly. The monthly tie is loose because polycarbonate margins follow BPA supply, Chinese capacity and electronics demand more than oil.
weak co-movement month to month · 249 months Show chartsHow to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.