Stumpage prices in Sweden 1909–2012: Testing for non-stationarity

The price of timber stumpage is one of the few natural-resource rents that can be directly observed as a market price. Rules for optimal timber harvesting under uncertainty have been found to depend on whether the timber rent price is non-stationary or stationary. In this study we extend previous research by Hultkrantz (1995) that tested for unit-root with an exogenous break point in Swedish stumpage prices from 1909 to 1990, employing data up to 2012, hence for 104 years, and unit-root tests with endogenously selected break points. We find support for a structural level break at the end of WW2 and that non-stationarity can be rejected. We show that this is a robust conclusion. There is thus no sign of a new break in the extended recent time period and no signal of a secular increase of timber resource scarcity.