Coal transport: Correlation
Prices it moves with, and why
Most coal moves by rail from mine to power plant or port, then by bulk ship. Rail freight rates are set by contracts and fuel surcharges, so they track diesel, labour and volumes more than the coal price itself.
Proxy US PPI: line-haul railroads index · monthly, Jan 2006 to Sep 2026There is no free public price for coal transport 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 linkCoal transport and Thermal coal
Monthly changes 0.21 weak correlation 12-month changes 0.66 moderate correlation Last 5 years 0.19 monthly changes Lead or lag +1 mo Thermal coal tends to lead by 1 month (r 0.35) Price function, Jan 2006 to Sep 2026 Coal transport ≈ 77.2 × (Thermal coal)0.22 R² 0.34 On this fit, a 10% higher thermal coal price goes with a 2.1% higher coal transport price over the long run. Units: index and $/mt.Chart: Coal transport and Thermal coal 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: Coal transport price against Thermal coal 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.Coal is the largest single commodity carried by many railways, including Indian Railways. The rail freight proxy tracks the Australian coal price weakly month to month, at 0.21, and moderately year to year, at 0.66, mostly through shared energy cycles.
weak co-movement month to month · 249 months Show chartsMine output sets how many trainloads are needed, and mines often contract rail capacity years ahead. The coal mining index correlates with rail rates at 0.16 for monthly moves and 0.50 for yearly moves.
little or none co-movement month to month · 249 months Show chartsThe farm energy proxy is the US diesel price, which also fuels most freight locomotives, and railways pass it on through fuel surcharges. Diesel leads rail rates by about two months, and yearly moves correlate at 0.74.
weak co-movement month to month · 249 months Show chartsRails, wagons and locomotives are made of steel, so steel affects railway capital costs. The rail proxy correlates with steel at 0.41 for monthly moves and 0.53 for yearly moves, partly because both follow industrial activity.
moderate co-movement month to month · 249 months Show chartsExport coal leaves ports in bulk carriers, and rail and sea freight both respond to trade volumes and fuel. The deep sea freight proxy correlates with rail rates at 0.30 for monthly moves and 0.67 for yearly moves.
weak co-movement month to month · 249 months Show chartsLocomotives and wagons are major capital costs for coal haulage. The railroad equipment proxy shows almost no link to rail freight rates, with monthly moves at 0.07, because equipment is priced on long orders.
little or none 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.