Lower-income countries...suffer the greatest shrinkage of the tax base as a result of corporate profit-shifting...[T]he multinational tax bases of some...countries could...be double their current size...We use the biggest international database of corporate accounts...to examine the extent of misalignment between economic activity and tax base. With a sample of around 1 million observations, relating to the activities of...25,000 corporate groups..., we assess the difference between the...location of profit and the actual distribution of...economic activity...The clearest finding from the analysis is that lower-income countries suffer the greatest losses...[I]t is...those jurisdictions with the highest per capita GDP that obtain a higher share of taxable profit than alignment with their economic activity would imply...Dutch losses of tax base would be around 50% were profits to be aligned with...tangible assets or workforce size – with only Luxembourg (losses around 80%)...more extreme...[E]liminating base erosion and profit-shifting may pose an existential threat for some jurisdictions...[T]he current approach – based...on tightening specific...areas of international tax rules – may not suffice to make substantial progress.