There have been some studies and conclusions therefrom about Debt to GDP ratio of a country and the econonomic growth rate. Some of the conclusions are:
1.once the debt to gdp ratio exceeds 77%, the growth rate will fall
2.for every 10 percentage points fall in debt to gdp ratio, growth rate will go up by 1.4%
These conclusions do not hold good in all situations and for all countries. Further fall or growth in growth rate depends also on the type or purpose for which the debt is incurred.
i.if the debt is maily for purposes of undertaking short gestation project like dams, irrigation canals, linking rivers with one another and with lakes etc. the growth rate will go up even if the debt to gdp ratio exceeds 100% or even 150%.
ii.if the debt is incurred for productive purposes like generation and distribution of electricity, import of technology, capital goods, raw materials etc. there will be no fall in growth rate even if the debt to gdp ratio is very high
iii. if the debt is incurred for unproductive purposes like increase in wages without increase in productivity, welfare measures, sports, entertainment etc. growth rate may fall with increase in debt, though in some cases, increase in spending power of the people may lead to increase in demand and consequently production.
iv. irrespecive of the debt-gdp ratio, economy would witness growth, if all able-bodied persons work and they put in their maximum possible ability, time, energy, attention etc to the work
v. the amount required for servicing the debt depends not only on the quantum of debt but also on interest rate. If the interest rate is low or nil, and the repayment period is long, serving debt may not be a big problem.