Poverty Impedes cognitive function
It is well documented that poor people have poor well-being. Children who experience poverty have lower rates of school completion and lower cognitive ability than others. While some theories claim that the lower cognitive ability of the poor is due to lower levels of formal education, others believe that the characteristics of the poor people are at play.
While the lab study is fascinating, a quasi-experimental approach taken by the authors is a clever way to test their idea in the field. They exploit a natural variation in income amongst Indian farmers. Amongst 464 randomly selected sugarcane farmers, who earn 60% of their income from sugarcane harvest were chosen for the study. These farmers experience cycles of poverty. Farmers are relatively rich after harvest and relatively poor before harvest. Although in randomized experiments, the control and treatment groups are usually different sets of people, in this case, the control group is the set of farmers after harvest and the treatment group is the same set of farmers before harvest. The same set of farmers were given the Raven's progressive matrix tasks to measure fluid intelligence and a version of the Stroop Tasks to measure spatial incompatibility, before and after the harvest. These are very commonly used tests in the literature. Results show that the farmers before harvest had lower scores on the tests than farmers after the harvest, on average. This indicates that financial troubles left the pre-harvest farmers with fewer cognitive resources.
To make sure that the results are causal rather than just correlational, the authors considered various alternative explanations. The authors deny the existence of a possible calendar effects owing to the fact that different farmers harvested their crop at different times. To check if farmers are indeed relatively poor before harvest, they took a survey of the farmers pre-harvest and post-harvest and found that farmers, in the pre-harvest period, pawned items at a higher rate, were more likely to take loans and were more likely to report that they had trouble paying their bills. The authors suggest that sugarcane farmers usually employ external labour and can accurately know their crop yield months before harvest. This is the basis for suggesting that physical exertion and anxiety over crop yield do not play a role in lower pre-harvest test scores. Perhaps farmers do better post-harvest because they are taking the test for the second time? To address this, the authors tested a subsample of farmers for the first time post-harvest and found that they had similar results to the farmers who took the test for the second time post-harvest. If the former set of farmer had done worse than the latter set, then learning on the test could have played a role. Although the authors find some evidence of learning on the error rates of the Stroop tasks they claim that overall, better performance post-harvest cannot be due to learning or training/effects.
The findings of this paper suggest that a sense of lack of resources leads to diminished cognitive function. It is not merely poverty but also thinking about poverty that causes the problem. The authors suggest that while studies estimate the monetary benefit of government support to the poor, they do not estimate a cognitive benefit and should rightly be doing so.
The rather accessible paper titled "Poverty Impedes Cognitive" can be found here.
Permanent link
A study by Mani, Mullainathan, Shafir and Zhao (2012) takes a different approach and suggest that a sense of scarcity of money leaves the poor with fewer cognitive resources to guide their action. In a lab experiment, they found that when people with lower incomes were induced to think about their daily financial troubles, they performed much worse on subsequent tasks measuring cognitive ability, than those who were not induced to think about financial troubles. For people with higher incomes, however, inducing thoughts of financial scarcity had no effect.
While the lab study is fascinating, a quasi-experimental approach taken by the authors is a clever way to test their idea in the field. They exploit a natural variation in income amongst Indian farmers. Amongst 464 randomly selected sugarcane farmers, who earn 60% of their income from sugarcane harvest were chosen for the study. These farmers experience cycles of poverty. Farmers are relatively rich after harvest and relatively poor before harvest. Although in randomized experiments, the control and treatment groups are usually different sets of people, in this case, the control group is the set of farmers after harvest and the treatment group is the same set of farmers before harvest. The same set of farmers were given the Raven's progressive matrix tasks to measure fluid intelligence and a version of the Stroop Tasks to measure spatial incompatibility, before and after the harvest. These are very commonly used tests in the literature. Results show that the farmers before harvest had lower scores on the tests than farmers after the harvest, on average. This indicates that financial troubles left the pre-harvest farmers with fewer cognitive resources.
To make sure that the results are causal rather than just correlational, the authors considered various alternative explanations. The authors deny the existence of a possible calendar effects owing to the fact that different farmers harvested their crop at different times. To check if farmers are indeed relatively poor before harvest, they took a survey of the farmers pre-harvest and post-harvest and found that farmers, in the pre-harvest period, pawned items at a higher rate, were more likely to take loans and were more likely to report that they had trouble paying their bills. The authors suggest that sugarcane farmers usually employ external labour and can accurately know their crop yield months before harvest. This is the basis for suggesting that physical exertion and anxiety over crop yield do not play a role in lower pre-harvest test scores. Perhaps farmers do better post-harvest because they are taking the test for the second time? To address this, the authors tested a subsample of farmers for the first time post-harvest and found that they had similar results to the farmers who took the test for the second time post-harvest. If the former set of farmer had done worse than the latter set, then learning on the test could have played a role. Although the authors find some evidence of learning on the error rates of the Stroop tasks they claim that overall, better performance post-harvest cannot be due to learning or training/effects.
The findings of this paper suggest that a sense of lack of resources leads to diminished cognitive function. It is not merely poverty but also thinking about poverty that causes the problem. The authors suggest that while studies estimate the monetary benefit of government support to the poor, they do not estimate a cognitive benefit and should rightly be doing so.
The rather accessible paper titled "Poverty Impedes Cognitive" can be found here.
Permanent link
Comments
Post a Comment