1、Isolating the “Tech” from EdTech: Experimental
Evidence on Computer Assisted Learning in China
NBER Working Paper No. 26953
Yue Ma
,
Stanford University
Robert Fairlie,
University of California
Prashant Loyalka,
Stanford University
Scott Rozelle,
Stanford University
EdTech which includes online education, computer assisted learning (CAL), and remote
instruction was expanding rapidly even before the current full-scale substitution for in-person
learning at all levels of education around the world because of the coronavirus pandemic.
Studies of CAL interventions have consistently found large positive effects, bolstering
arguments for the widespread use of EdTech. However CAL programs, often held after school,
provide not only computer-based instruction, but often additional non-technology based inputs
such as more time on learning and instructional support by facilitators. In this paper, we develop
a theoretical model to carefully explore the possible channels by which CAL programs might
affect academic outcomes among schoolchildren. We isolate and test the technology-based
effects of CAL and additional parameters from the theoretical model, by designing a novel
multi-treatment field experiment with more than four thousand schoolchildren in rural China.
Although we find evidence of positive overall CAL program effects on academic outcomes,
when we isolate the technology-based effect of CAL (over and above traditional pencil-andpaper learning) we generally find small to null effects. Our empirical results suggest that, at
times, the “Tech” in EdTech may have relatively small effects on academic outcomes, which
has important implications for the continued, rapid expansion of technologies such as CAL
throughout the world.
原文链接:
https://www.nber.org/papers/w26953
.pdf
2、Demographic Determinants of Testing Incidence and COVID-19 Infections in New York City Neighborhoods
NBER Working Paper No. 26954
George J. Borjas
,
Harvard Kennedy School
New York City is the hot spot of the COVID-19 pandemic in the United States. This paper
merges information on the number of tests and the number of infections at the New York City zip
code level with demographic and socioeconomic information from the decennial census and the
American Community Surveys. People residing in poor or immigrant neighborhoods were less
likely to be tested; but the likelihood that a test was positive was larger in those neighborhoods,
as well as in neighborhoods with larger households or predominantly black populations. The rate
of infection in the population depends on both the frequency of tests and on the fraction of
positive tests among those tested. The non-randomness in testing across New York City
neighborhoods indicates that the observed correlation between the rate of infection and the
socioeconomic characteristics of a community tells an incomplete story of how the pandemic
evolved in a congested urban setting.