Labor Share of GDP

Studying labor market is important for number of reasons. One of the key ones is that labor wages, salaries and benefits account for about 70% of the country's GDP. Nevertheless, since 2010 we witnessed a decrease in the 'labor share' of GDP. Think of two different potential economic explanations for this and using bullet points describe how would you empirically test one of your two hypothesis/explanations. Hint: think about the papers you read --- what were their hypothesis, what data did they use, what assumption they made, how did they make sure that what they observe is a causal relationship and not a pure correlation, etc.