Multivariate Tobit models are estimated using German cross–sectional data to test whether strategic complementarities exist between expenditures in four different types of ICT–components. If two ICT–components are complements, they are correlated (provided that agents act rationally). Significant correlations between all four types of ICT–expenditures are found and can neither be removed by ‘standard’ firm heterogeneity control variables such as firm size, firms’ workforce qualification structure nor by firms’ ICT–structure so that indication for the presence of complementarities is provided.


Kaiser, Ulrich


strategic complementarity, ICT–investment, multivariate Tobit model