TABLE 10.1 Median net interest-bearing debt-to-book equity and net interest-bearing debt-to-market equity for selected European industries in 19922011 Interest-bearing debt-to-book equity All listed firms Large listed firms 17% Industry Computer programming and data Processing Pharmaceutical Heavy construction Air transportation Electric services Truck, auto rental and leasing 40% 92% 114% 140% 244% 24% 47% 147% 131% 148% 229% Provide one potential explanation for the heterogeneity in debt ratios in the undustries shown in the figure above. TABLE 10.1 Median net interest-bearing debt-to-book equity and net interest-bearing debt-to-market equity for selected European industries in 19922011 Interest-bearing debt-to-book equity All listed firms Large listed firms 17% Industry Computer programming and data Processing Pharmaceutical Heavy construction Air transportation Electric services Truck, auto rental and leasing 40% 92% 114% 140% 244% 24% 47% 147% 131% 148% 229% Provide one potential explanation for the heterogeneity in debt ratios in the undustries shown in the figure above