Research

Publications and Working Papers

Receiving vs. believing (mis)information from friends

Experimental evidence from India.

Social Networks

Belief Formation

Working paper

How much do people (additionally) believe a news story because it’s been shared by a friend? How much should they believe it for that reason? To answer these questions we conduct a series of lab experiments in India with ~800 pairs of real-life friends. Using a custom platform, we collect detailed information on how individuals (sharers) decide which stories to share, and how their friends (receivers) update their beliefs in response. We find receivers over-interpret sharing as a sign of a story’s veracity and the sharer’s faith in it, while discounting other reasons/motivations for sharing. As a result, receivers’ trust in shared stories increases irrespective of the sharers’ belief in them, with false stories accruing the greatest additional trust. To identify mechanisms, I measure how receivers update if, instead of observing their friend’s decisions they (i) learn their friend’s beliefs, and (ii) receive computer-generated clues of known accuracy (instead of subjective signals from their friend). I find several mechanisms contribute to receivers’ biased inference: receivers overestimate how well sharers’ beliefs predict a story’s veracity; miscalculate the relevance of those beliefs to sharing decisions; and exhibit base-rate neglect, updating the most on stories they least believed originally.

The American Dream in the Great Depression

Absolute Income Mobility in the United States, 1915-1940

Inequality

Income mobility

Working paper

We use two newly digitized historical datasets to estimate rates of absolute income mobility for the cohort of sons born in the early 1910s in the United States. We find that the mobility for this cohort was 30-50 percentage points lower than for the 1940 cohort, a finding robust to alternative income imputations, inflation indices and age adjustments. The rates are similar to men born in the United States in the 1980s, suggesting that today’s young adults face mobility prospects comparable to those of adults entering the labor market during the Great Depression. But while low mobility rates for men born in the 1910s were due mainly to slow economic growth during the Depression, those of men coming of age today are due mostly to rising income inequality.

James Feigenbaum, Maximillian Hell, Robert Manduca, Jimmy Narang

The Fading American Dream

Trends in absolute income mobility since 1940

Inequality

Income mobility

We estimated rates of absolute income mobility — the fraction of children who earn more than their parents — by combining data from U.S. Census and Current Population Survey cross sections with panel data from de-identified tax records. We found that rates of absolute mobility have fallen from approximately 90% for children born in 1940 to 50% for children born in the 1980s. Increasing Gross Domestic Product (GDP) growth rates alone cannot restore absolute mobility to the rates experienced by children born in the 1940s. However, distributing current GDP growth more equally across income groups as in the 1940 birth cohort would reverse more than 70% of the decline in mobility. These results imply that reviving the “American dream” of high rates of absolute mobility would require economic growth that is shared more broadly across the income distribution.

Raj Chetty, Nathaniel Hendren, David Grusky, Maximillian Hell, Robert Manduca, Jimmy Narang

10.1126/science.aal4617

In Progress

Priors vs. Desires: what happens when biases interact

Belief Formation

In Progress

A long literature in psychology and economics documents that people update their beliefs in a biased manner upon receiving news that agrees with their priors (confirmation bias) or their desires (motivated updating / desirability bias). But what happens when these biases (i) align or (ii) conflict with each other? By combining data from existing studies with new experiments, I find that confirmation bias is first-order, and mediates the extent to which desirability bias occurs. Subjects’ beliefs show almost no movement upon receiving news that confirms their priors, irrespective of its favorability to their ego or politics. However, subjects update their beliefs considerably upon receiving disconfirming (surprising) news, with larger updates on favorable news.

Evaluating Satyameva Jayate: A digital literacy program to reduce misinformation among high school students

Social Networks

Belief Formation

In Progress

In partnership with the government of Kerala (India), this randomized study will evaluate the effectiveness of a digital literacy program to reduce the spread of misinformation among high school students. The program, titled Satyameva Jayate , is mandatory for the nearly three million students enrolled in government schools. We plan to introduce new curriculum and treatments in addition to evaluating the program’s current version.

Jimmy Narang, Mir Mohammed Ali