Caustic soda: Correlation
Prices it moves with, and why
Caustic soda and chlorine are made together by passing electricity through brine. Output is usually set by chlorine demand, so caustic soda prices depend on chlorine and PVC demand, power costs, and demand from alumina, paper and textiles.
Proxy US PPI: alkalies and chlorine index (BLS base period) · monthly, Jan 2006 to Sep 2026There is no free public price for caustic soda 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 linkCaustic soda and Salt
Monthly changes -0.10 little or none correlation 12-month changes -0.09 little or none correlation Lead or lag −5 mo Caustic soda tends to lead by 5 months (r 0.15) Price function, Jan 2006 to Aug 2026 Caustic soda ≈ 3.47 × (Salt)0.86 R² 0.61 On this fit, a 10% higher salt price goes with a 8.6% higher caustic soda price over the long run. Units: index (BLS base period) and index, BLS base period.Chart: Caustic soda and Salt 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: Caustic soda price against Salt 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.Every tonne of chlorine comes with a fixed amount of caustic soda, so the two are made together. When PVC demand is strong, more caustic is made and its price weakens. Both use the same US index here, so no statistics are shown.
Not enough overlapping price history to measure.Brine made from salt is the raw material, but salt is cheap compared with power. The data shows no link: monthly moves correlate at minus 0.10 and yearly moves at minus 0.09.
little or none co-movement month to month · 162 months Show chartsElectrolysis uses a lot of electricity, the largest cost of making caustic soda and chlorine. The proxy is the US industrial power price; monthly moves correlate at 0.14 and yearly moves at 0.46, as power contracts adjust slowly.
little or none co-movement month to month · 249 months Show chartsAlumina refineries dissolve bauxite in caustic soda, a large share of demand. The aluminium price shows little link with the proxy, slightly negative: monthly moves correlate at minus 0.14, as the index mixes caustic with chlorine and soda ash.
little or none co-movement month to month · 249 months Show chartsMost chlorine goes into PVC, so strong PVC demand raises chlorine output and the caustic soda that comes with it. The PVC proxy is a broad plastics index; monthly moves correlate at 0.08 and yearly moves at 0.08.
little or none co-movement month to month · 249 months Show chartsViscose fibre makers dissolve wood pulp with caustic soda, a large demand in India and China. Viscose has no public price series here, so the link is shown as text only.
Not enough overlapping price history to measure.How 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.