If these constraints are not in place, however, analysts can no longer ignore this difference because the economy can then engage in
nonproductive activity that for many years can force up the
debt burden and add to GDP.
When China was underinvested, investments were nearly always productive, and so the ability to ignore budget constraints and hide the costs of
nonproductive investment in the form of rising
debt had little effect on the GDP data — or, to put it differently, rising
debt did not reflect a rising
debt burden.