The Earned Income Tax Credit and Maternal Time Use: More Time Working and Less Time with Kids?

Parents spend considerable sums investing in their children’s development, with their own time among the most important forms of investment. Given well-documented effects of the Earned Income Tax Credit (EITC) on maternal labor supply, it is natural to ask how the EITC affects other time allocation decisions, especially time with children. We use the American Time Use Surveys to study the effects of EITC expansions since 2003 on time devoted to a broad array of activities, with considerable attention to the amount and nature of time spent with children. Our results confirm prior evidence that the EITC increases maternal work and reduces time devoted to home production and leisure. More novel, we show that the EITC also reduces time spent with children; however, almost none of the reduction comes from time devoted to “investment” activities. Effects are concentrated among socioeconomically disadvantaged mothers, especially those that are unmarried. Results are also most apparent for mothers of young children. Altogether, our results suggest that the increased work associated with EITC expansions over time has done little to reduce the time mothers devote to active learning and development activities with their children

New Evidence on the Effect of Public Policy on Employment, Intergenerational Mobility, Family Structure, and Social Attitudes Towards Working Women

My dissertation finds new evidence that public policy can be used to reduce poverty, increase economic opportunity, and encourage egalitarian social attitudes in the United States. I focus on the Earned Income Tax Credit (EITC), a wage subsidy that has become one of the most important parts of the U.S. social safety net. By 2013, the EITC redistributed $66 billion to over 28 million low-income households and lifted 9.4 million individuals out of poverty. I show that the EITC affects mothers’ labor-market outcomes, the education and earnings of children of EITC recipients, marriage and fertility decisions, and social attitudes towards working women. Chapter 1: The rise of working mothers radically changed the U.S. economy and the role of women in society. In one of the first studies of the 1975 EITC, I find that this program increased maternal employment by 7 percent, representing one million mothers. The EITC can help explain why the U.S. has long had such a high fraction of working mothers despite few childcare subsidies or parental-leave policies. This influx of working mothers likely had subsequent effects on the country: I find evidence that the EITC affected social attitudes and led to higher approval of working women. Chapter 2: Using four decades of variation in the federal and state EITC, we estimate the impact of the EITC on education and employment outcomes on children exposed to EITC expansions in childhood. Reduced-form results suggest that an additional$1,000 in EITC exposure when a child is 13 to 18 years old increases the likelihood of completing high school (1.3 percent), completing college (4.2 percent), being employed as a young adult (1.0 percent), and earnings by 2.2 percent. Instrumental variables analysis reveals that the primary channel through which the EITC improves these outcomes is increases in pre-tax family earnings. Chapter 3: There has long been a concern that public assistance programs in the U.S. discourage marriage among lower-income couples. The EITC provides a marriage bonus to some couples but a marriage penalty to others, and encourages some households to have more children but others to have less. The overall average effect of the EITC is therefore theoretically ambiguous and existing empirical evidence has been mixed. Using over 30 years of household panel data – and a novel approach that controls for current fertility and marital status – I find that state EITC expansions have positive average effects on both fertility and marriage. Marriage effects are largest for currently unmarried adults and give pause to concerns about the negative effects of the EITC on marriage. These results also imply that some estimates in the EITC literature may be biased, since endogenous switching from the control to the treatment group (defined by marital status or number of children) would violate the stable-group-composition condition required by difference in differences.PhDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/140804/1/jacobbas_1.pd

From cash to crickets:The non-monetary value of a resource can promote human cooperation

Enhancing human cooperation in the use of limited and depletable resources is of central concern to environmental management and human welfare. Behavioral models of cooperation have, to date, focused on inter-party dynamics such as reciprocity, punishment, or reputation in distribution of resources generally indexed by points, money, or effort. We argue that these models fail to account for a key driver of cooperative behavior – the non-monetary value people attach to resources. Across two behavioral experiments we model the effect of attaching non-monetary value to a resource within a resource dilemma game. When players believed that exhausting a resource would lead to the immediate death of live crickets they reduced personal consumption, equating to increased cooperation and greater collective benefit, relative to players given the standard instructions. Our findings provide insight into a largely untapped avenue through which to leverage cooperative behavior; emphasizing the non-monetary and non-tradable value of a resource

In-flight positional and energy use data set of a DJI Matrice 100 quadcopter for small package delivery

We autonomously direct a small quadcopter package delivery Uncrewed Aerial Vehicle (UAV) or "drone" to take off, fly a specified route, and land for a total of 209 flights while varying a set of operational parameters. The vehicle was equipped with onboard sensors, including GPS, IMU, voltage and current sensors, and an ultrasonic anemometer, to collect high-resolution data on the inertial states, wind speed, and power consumption. Operational parameters, such as commanded ground speed, payload, and cruise altitude, are varied for each flight. This large data set has a total flight time of 10 hours and 45 minutes and was collected from April to October of 2019 covering a total distance of approximately 65 kilometers. The data collected were validated by comparing flights with similar operational parameters. We believe these data will be of great interest to the research and industrial communities, who can use the data to improve UAV designs, safety, and energy efficiency, as well as advance the physical understanding of in-flight operations for package delivery drones.Comment: 13 pages, 11 figures, submitted to Scientific Dat

A numerical stability analysis for the Einstein-Vlasov system

We investigate stability issues for steady states of the spherically symmetric Einstein-Vlasov system numerically in Schwarzschild, maximal areal, and Eddington-Finkelstein coordinates. Across all coordinate systems we confirm the conjecture that the first binding energy maximum along a one-parameter family of steady states signals the onset of instability. Beyond this maximum perturbed solutions either collapse to a black hole, form heteroclinic orbits, or eventually fully disperse. Contrary to earlier research, we find that a negative binding energy does not necessarily correspond to fully dispersing solutions. We also comment on the so-called turning point principle from the viewpoint of our numerical results. The physical reliability of the latter is strengthened by obtaining consistent results in the three different coordinate systems and by the systematic use of dynamically accessible perturbations.Comment: 35 pages, 12 figure

Australian Red Wines Made from Non-Traditional, Emerging Red Grape Varieties: Distinguishing Sensory Profiles and Consumer Perceptions

To sustain the Australian wine sector, it needs to adopt innovative strategies to adapt to rising temperatures brought by climate change. A potential approach is cultivating more drought-resistant emerging grape varieties with diverse flavour profiles to reduce, in part, the current reliance on major varieties. The study aimed to 1) explore sensory profiles of Australian wines made from three emerging red wine grape varieties, 2) determine consumer perceptions and liking of these wines and 3) evaluate whether these three emerging varietal wines display similar sensory characteristics to three major Australian varietal wines. An expert sensory panel (n = 8) performed a sorting task with 38 commercially available Australian wines (10 Montepulciano, 10 Nero d’Avola and 9 Touriga Nacional) and three each produced from Shiraz, Grenache and Cabernet-Sauvignon for exploration of sensory similarity and quality screening purposes, with three wines removed from further study. A Rate-All-That-Apply (RATA) panel of trained wine tasters (n = 36) evaluated the wines to produce sensory profiles and collect preliminary liking. Finally, a subset (n = 9 total) of the emerging wines was selected for consumer trials. Red wine consumers (n = 116) liked all wine samples independent of their knowledge and wine behaviour. Similarity scores indicated that consumers found the most significant similarity between Shiraz and Montepulciano, and Cabernet-Sauvignon and Touriga Nacional wines. The expert and trained tasters also drew similar comparisons between Shiraz and Montepulciano, but also between Grenache and Nero d’Avola wines, yet not towards Cabernet-Sauvignon and Touriga Nacional wines. The findings support the consumer acceptance and perceived similarities between the sensory profile of Shiraz and Montepulciano and Nero d’Avola and Grenache varietal wines, highlighting the potential for producers to adopt these more drought-resistant varieties as alternatives in a warmer future

Sci-Hub provides access to nearly all scholarly literature

The website Sci-Hub enables users to download PDF versions of scholarly articles, including many articles that are paywalled at their journal\u27s site. Sci-Hub has grown rapidly since its creation in 2011, but the extent of its coverage was unclear. Here we report that, as of March 2017, Sci-Hub\u27s database contains 68.9% of the 81.6 million scholarly articles registered with Crossref and 85.1% of articles published in toll access journals. We find that coverage varies by discipline and publisher, and that Sci-Hub preferentially covers popular, paywalled content. For toll access articles, we find that Sci-Hub provides greater coverage than the University of Pennsylvania, a major research university in the United States. Green open access to toll access articles via licit services, on the other hand, remains quite limited. Our interactive browser at https://greenelab.github.io/scihub allows users to explore these findings in more detail. For the first time, nearly all scholarly literature is available gratis to anyone with an Internet connection, suggesting the toll access business model may become unsustainable