Calculation of the component

In national accounts the expenditure for transport by private households are published in Beiheft zur Fachserie 18: Private Konsumausgaben und Verfügbares Einkommen, Tab. 2.10 „Konsumausgaben der p. H. im Inland nach Verwendungszwecken u. Dauerhaftigkeit der Güter“ (SEA-Nr. 07). The share of work- or education related transport of total traffic can be calculated using specifications regarding commuter traffic in the table „Verkehrsarten nach Fahrtzwecken“ in DIW (versch. Jahrgänge): „Verkehr in Zahlen“. Data is available for 1990, 1993, 1994 as well as every second year between 1994 and 2001 and every year of the period between 2002 and 2014.

For yeas with missing data we interpolate between data before and after the respective year. To improve the comparability of cost in this framework, we correct values between 1991 and 2001. Due to the data availability this can only be done with a rather rough estimation: We take the largest change between two years in the total period (work commuting: 0,45 percentage points, education commuting: 0,23 percentage points) and assume that this is the change between 2001 and 2002. The plus/minus sign is determined by the trend in the previous period.

Subsequently, the total transport expenditures are weighted with the share of work- or education related transport; the resulting amount is price-adjusted with the usual procedure.