Search

We document the magnitudes of and mechanisms behind socioeconomic differences in travel behavior during the COVID‐19 pandemic. We focus on King County, Washington, one of the first places in North America where COVID‐19 was detected. We leverage novel and rich administrative and survey data on travel volumes, modes, and preferences for different demographic groups. Large average declines in travel and public transit use due to the pandemic and related policy responses mask substantial heterogeneity across socioeconomic groups. Travel declined considerably less among less‐educated and lower‐income individuals, even after accounting for mode substitution and variation across neighborhoods in the impacts of public transit service reductions. As policy became less restrictive and travel increased, the size of the socioeconomic gap in travel behavior remained stable, and remote work capabilities became increasingly important in explaining this gap. Our results imply that disparities in travel behavior across socioeconomic groups may become an enduring feature of the urban landscape.

Homelessness may be both a cause of and one of the more extreme outcomes of poverty. Governments at all levels and private organizations have a variety of tools to combat homelessness, and these strategies have changed dramatically over the past quarter century. In this paper, we catalog the policy responses and the existing literature on the effectiveness of these strategies, focusing on studies of individual‐level effects from randomized controlled trial evaluations and the best quasi‐experimental designs. We conclude by discussing outstanding questions that can be addressed with these same methods.

Housing instability for low-income renters has drawn greater attention recently, but measurement has limited research on policies to stabilize housing. Address histories from consumer reference data can be used to increase the quantity and quality of research on low-income renters. Consumer data track housing moves throughout the entire United States for most of the adult population. In this article, I show that such data can measure housing stability for groups with very low income and extreme instability. For example, the data can track housing moves during natural disasters, at demolition of public housing, for households at high risk of homelessness, and during gentrification. Consumer data can track housing instability outcomes that are more common than shelter entry and less expensive to collect than surveys. Relative to existing administrative address histories, consumer data allow researchers to track housing moves to exact addresses and across jurisdictions.

Does emergency financial assistance reduce criminal behavior among those experiencing negative shocks? To address this question, we exploit quasi-random variation in the allocation of temporary financial assistance to eligible individuals and families that have experienced an economic shock. Chicago's Homelessness Prevention Call Center (HPCC) connects such families and individuals with assistance, but the availability of funding varies unpredictably. Consequently, we can determine the impact of temporary assistance on crime by comparing outcomes for those who call when funds are available to those who call when no funds are available. Linking this call center information to arrest records from the Chicago Police Department, we find some evidence that total arrests fall between 1 and 2 years after the call. For violent crime, police arrest those for whom funds were available 51% less often than those who were eligible but for whom no funds were available. Single individuals drive this decrease. The decline in crime appears to be related, in part, to greater housing stability—being referred to assistance significantly decreases arrests for homelessness-related, outdoor crimes such as trespassing. However, we also find that financial assistance leads to an increase in property crime arrests. This increase is evident for family heads, but not single individuals; the increase is mostly due to shoplifting; and the timing of this increase suggests that financial assistance enables some families to take on financial obligations that they are subsequently unable to meet. Overall, the change in the mix of crime induced by financial assistance generates considerable social benefits due to the greater social cost of violence.

Does providing financial assistance to people who have just experienced an income shock affect their healthcare use? To address this question, we examine healthcare outcomes in a setting where people at risk of homelessness due to an income shock were offered or denied referral to financial assistance quasi-randomly. Among callers who have been screened as eligible for assistance at Chicago’s Homelessness Prevention Call Center (HPCC), some are denied assistance because the availability of funding varies. Conditional on some observable characteristics, funding availability is as-good-as-randomly assigned to callers. We link callers to healthcare utilization records and observe their inpatient hospital stays and emergency department visits. We find that referral to financial assistance has little effect on overall healthcare use–we can reject increases in total utilization greater than 7% of the base rate and decreases of more than 4%. This null effect can be explained, in part, by the fact that the income shock does not significantly change overall healthcare use among those not receiving assistance, suggesting that these individuals can insure health and healthcare demand against these shocks in other ways.

Housing instability for low-income renters has drawn greater attention recently, but measurement has limited research on policies to stabilize housing. Address histories from consumer reference data can be used to increase the quantity and quality of research on low-income renters. Consumer data track housing moves throughout the entire United States for most of the adult population. In this article, I show that such data can measure housing stability for groups with very low income and extreme instability. For example, the data can track housing moves during natural disasters, at demolition of public housing, for households at high risk of homelessness, and during gentrification. Consumer data can track housing instability outcomes that are more common than shelter entry and less expensive to collect than surveys. Relative to existing administrative address histories, consumer data allow researchers to track housing moves to exact addresses and across jurisdictions.

I use a correspondence study of the low-wage labor market in Washington, DC to test whether employers discriminate against applicants who live farther from the job location. Fictional resumes randomly assigned to addresses far from the job location receive 14 percent fewer callbacks than those with addresses in nearby but similarly affluent neighborhoods. Living five to six miles away from the job results in a penalty equal to that received by applicants with stereotypically black names. On the other hand, holding commute distance constant, I find no statistical evidence that employers respond to a neighborhood's affluence. [ABSTRACT FROM AUTHOR]

Public appeals regarding criminal justice have shifted somewhat from “tough on crime” to “smart justice” that is more lenient when tradeoffs merit it. Among other considerations, smart sentencing policy depends on how sentence severity affects recidivism. Using administrative data on two common non-violent felonies committed by adults in Michigan, we measure the effect of sentences on offenders' future criminal activity. Discontinuities in the legislative guidelines that constrain sentences chosen by Michigan judges provide exogenous variation in sentence severity. Harsher sentences generated by sentencing guidelines significantly reduce recidivism by felony shoplifters but not repeat drunk drivers. Recidivism falls most for young, male offenders from Southeast Michigan and varies non-monotonically with prior criminal record. Because of such heterogeneity, any empirical strategy measures a local average treatment effect relevant to a particular population of offenders. Contrary to our main results, we find no evidence that harsher sentences induced by judge assignments reduce recidivism in our sample. When sentencing guidelines provide the primary practical policy lever, “smart justice” should incorporate directly relevant empirical evidence that accounts for offense- and offender-specific tradeoffs between public safety and the public budget.

This paper investigates the effectiveness of sterilized foreign exchange interventions by exploiting a discontinuous policy rule used by the Central Bank of Colombia. We use a unique data set that comprises tick by tick intervention and order book data, daily capital in- and outflows, and balance sheet information of financial institutions. We apply regression discontinuity methods to identify the surprise component of rule-based interventions and use this variation to measure how they affect exchange rates and capital flows. Our findings indicate that interventions had significant effects on the exchange rate, albeit short-lived (2–3 weeks). Moreover, capital controls amplify the effect of intervention, though some effect remains even in the presence of free capital flows. A methodological contribution of the paper is to extend regression discontinuity designs to a time-series environment and to show how these techniques can be used to identify and estimate local non-linear impulse response functions. A clearly defined policy rule and high frequency data are crucial in exploiting local variation around the policy cutoff.

Previous literature highlights a robust relationship between schools and longer term criminal outcomes. The research presented here examines the short term effects of school being in-session on crime. We begin by confirming the findings of Jacob and Lefgren (2003) that teacher in-service days lead to a reduction in violent crime, consistent with a role for social interactions in school. We extend this result by showing that schools populated with more high crime risk students have larger decreases in crime on teacher in-service days but that this effect is reversed for schools with mostly low crime risk students. These results provide evidence that concentrating high crime risk students into particular schools increases local crime.

Despite being eligible for use in any neighborhood, housing choice vouchers tend to be redeemed in low-opportunity neighborhoods. This paper investigates how landlords contribute to this outcome and how they respond to efforts to change it. We leverage a policy change in Washington, DC, that increased voucher rental payments only in high-rent neighborhoods. Using two waves of a correspondence experiment that bracket the policy change, we show that most opportunity landlords screen out prospective voucher tenants, and we detect no change in average screening behavior after a $450 per month increase in voucher payments. In lease-up data, however, enough landlords do respond to increased payments to equalize the flow of voucher tenants into high- vs. low-rent neighborhoods. Using tax data and listings from a website specializing in subsidized housing, we characterize a group of marginal opportunity landlords who respond to higher payments. Marginal opportunity landlords are relatively rare, list their units near market rates, operate on a small scale, and negatively select into the voucher program based on hard-to-observe differences in unit quality.

Despite being eligible for use in any neighborhood, housing choice vouchers tend to be redeemed in low-opportunity neighborhoods. This paper investigates whether landlord behavior contributes to this outcome by studying the recent expansion of neighborhood-based voucher limits in Washington, DC. We conduct two waves of a correspondence experiment: one before and one after the expansion. Landlords heavily penalize tenants who indicate a desire to pay by voucher. The voucher penalty is larger in high-rent neighborhoods, pushing voucher tenants to low-rent neighborhoods. We find no evidence that indexing rents to small areas affects landlord acceptance of voucher tenants. The data can reject the claim that increasing rent limits by less than $3,000 per month can eliminate the voucher penalty. Neighborhood rent limits do shift lease-up locations toward high-rent neighborhoods in the year after the policy change, an effect that is large relative to the number of voucher households that move but small relative to all voucher tenants.

Researchers commonly measure discrimination by comparing responses to multiple fictional applicants sent to the same vacancy. I find evidence that these applications interact. Using data from several existing experiments, I find that applicants randomly assigned to compete against higher quality applicant pools receive more callbacks. In the presence of such spillovers, many experiments confound discrimination against an individual's characteristics with employers’ responses to the composition of the applicant pool. Under one reasonable set of assumptions, adjusting for applicant pool composition increases measured discrimination by 30% on average. Avoiding experimental designs that stratify treatment assignment by vacancy can eliminate such confounding.

Landlords in high-opportunity neighborhoods screen out tenants using vouchers. In our correspondence experiment, signaling voucher status cuts landlord responses in half. This voucher penalty increases with posted rent and varies little with signals of tenant quality and race. We repeat the experiment after a policy change and test how landlords respond to raising voucher payment limits by $450 per month in high-rent neighborhoods. Most landlords do not change their screening behavior; those who do respond are few and operate at small scale. Our results suggest a successful, systematic policy of moving to opportunity would require more direct engagement with landlords.

Can temporary shocks to training and early career experience permanently reduce productivity? Using detailed data on the careers and productivity of Major League Baseball players subject to the Vietnam War draft, we find that birth dates randomly drawn in the draft produce 19 percent fewer major league players. Players born on draft days who do make it to Major League Baseball produce 29 percent fewer wins than those born on nondraft days, a gap that is largest for the most productive players and persists as players age. In addition, the tendency of the draft to push men toward more schooling generates at least some of our results.

We test whether public transit access affects crime using a novel identification strategy based on temporary, maintenance-related closures of stations in the Washington, DC rail transit system. The closures generate plausibly exogenous variation in transit access across space and time, allowing us to test the popular notion that crime can be facilitated by public transit. Closing one station reduces crime by 5% in the vicinity of stations on the same train line. Most of this effect remains after controlling for decreased ridership, indicating that a decrease in the availability of victims does not drive most of our results. We find suggestive evidence that crime falls more at stations that tend to import crime, i.e. stations where perpetrators are less likely to live. We also see larger decreases at stations on the same line when the transit authority closes stations that tend to export crime. These heterogeneous effects suggest that the response of perpetrators to increased transportation costs contributes to the decrease in crime.

Do transportation costs constrain job search in urban low wage labor markets? I test this question by providing transit subsidies to randomly selected clients of a non-profit employment agency. The subsidies generate a large, short-run increase in search intensity for a transit subsidy group relative to a control group receiving standard job search services but no transit subsidy. In the first two weeks, individuals assigned to the transit subsidy group apply and interview for 19% more jobs than those not receiving subsidies. The subsidies generate the greatest increase in search intensity for individuals living far from employment opportunities. Some suggestive evidence indicates that greater search intensity translates into shorter unemployment durations. These results provide experimental evidence in support of the theory that search costs over space can depress job search intensity, contributing to persistent urban poverty in neighborhoods far from job opportunities.

Can governments in developing countries retain skilled health workers by raising public sector wages? We investigate this question using sudden, policy-induced wage variation in which the Government of Ghana restructured the pay scale for health workers employed by the government. We find that a 10% increase in wages decreases annual attrition from the public payroll by 1.0 percentage point (from a mean of 8 percentage points) among 20–35 year-old workers from professions that tend to migrate. As a result, the ten-year survival probability for these health workers increases from 0.43 to 0.49. The effects are concentrated among these young workers, and we do not detect effects for older workers or among categories of workers that do not tend to migrate. Given that Ghana was a major source of skilled health professional migrants during this period and that our attrition measure correlates strongly with aggregate migration, we interpret these results as evidence that wage increases in Ghana improved retention mainly through reducing international migration.

A relatively undocumented, though well-known, problem associated with the generally prevalent antifouling and fouling release underwater ship hull coatings can be termed “long-term paint degradation.” This problem can result in a fuel penalty of 25-40% on a hull that has not been fully blasted and recoated for 10-15 years. This paper examines the causes of and solutions to this problem.

Does lineup protection exist? Observers of baseball frequently invoke the idea of lineup protection in which a batter will walk less and hit for more power if he is followed in the batting order by a high-quality hitter. Previous attempts to measure protection in Major League Baseball have sometimes found evidence of lower walk rates but never an impact on power hitting. I argue that these efforts fail to uncover such evidence because lineups are selectively chosen by managers, introducing endogeneity bias into ordinary linear regression and batting split comparisons. To remedy this problem, I use injuries to batters protectors as a natural experiment that quasi-randomly changes the level of protection received by batters. Using this approach, I find evidence that protected batters hit for more power, hitting 9.7 percent more extra-base hits if the protectors OPS is 100 points higher. These effects are strongest among 3rd hitters, who hit 26 percent more extra-base hits under the same scenario. Supporting the previous literature, I find that batters walk more, especially intentionally, when left unprotected.

Objectives To identify the availability and interest in the adoption of e-textbooks by a school of pharmacy's students and faculty. Methods An initial identification of all required and suggested textbooks used within a school of pharmacy's required courses was completed. Two anonymous questionnaires ( Appendix A ) were then administered through an online survey instrument to both students and faculty via a link in an e-mail asking for voluntary participation. Results Responses were received from 41% of faculty and 42% of students. Seventy percent of required textbooks and 33% of suggested textbooks were available for purchase in an e-book format. Responses to the survey questions revealed that printed textbooks were preferred over electronic textbooks by students (78.7%) and faculty (84%). Factors that affected their decision to use printed or electronic textbooks were also identified. Conclusions Electronic books have the potential to offer many benefits to readers. However, it appears that students and faculty at this school of pharmacy are not interested in adopting electronic textbooks at this time. As the availability of electronic textbooks increases and people become more aware of their capabilities, future surveys may reveal a change in students' and faculty's attitudes toward this medium.

The new technique of organic particulate analysis (OPA) has been employed to evaluate the thermal decomposition of metal acetylacetonate chelates. Of the 23 compounds thus evaluated, 13 were found to give organoparticulation signals at temperatures In an attempt to characterize the nature of the particulates derived from these compounds, mass-spectral data were obtained on the effluent species arising from the thermal decompositions of the strongest particulate emitting metal acetylacetonates. The results showed that acetylacetone was the major component identified in both particulate and vapor effluents. With the exception of Cr(III) acetylacetonate, no metal was detected in these effluents. The OPA technique enabled the relative thermal stabilities of the metal acetylacetonates to be ascertained. Zn acetylacetonate was found to have the lowest thermal stability and the alkaline earth compounds the highest; the transition metal acetylacetonates exhibit intermediate thermal stabilities. Since a certain critical minimum particulate size (i.e., 25 A) seems to be necessary to produce a response on the ion chamber detector instrument, vapor-phase association of acetylacetone molecules may be occurring. This association would most probably occur through H-bonded species involving the enol form of the 1,3-diketone.

The electrochemically initiated polymerization of styrene in methylene chloride solvent with the use of platinum electrodes and tetraalkyl and -aryl group VA halides (i.e., quaternary ammonium, phosphonium, and arsonium compounds) as electrolyte has been investigated. The order of reactivity of the electrolytes with respect to polymerization rate and initiation efficiency was found to be: arsonium > phosphonium > ammonium. Mechanisms involving the electroreduction of the group VA quaternary halides to species capable of electroinitiating polymerization are postulated. The observed losses in solution conductivities during polymerization with the quaternary phosphonium and arsonium electrolytes indicate possible interaction between the initiating radical-ionic species and the supporting electrolyte. In an attempt to further elucidate the mechanism of initiation in these systems, a separate series of experiments, employing the nonpolymerizing monomer, 1,1-diphenylethylene, has been carried out.

The thermal decompositions of a series of diazonium compounds have been investigated using the new technique of organic particulate analyses (OPA). This extremely sensitive technique makes possible the detection of particulates emitted from the diazonium compounds during thermal decomposition. The submicron particulates derived in this fashion are readily detectable by their influence on the output current of an ion chamber detector or by their effect on the cloud chamber of a condensation nuclei monitor. Of the 14 diazonium compounds evaluated, 11 were found to exhibit particulation behavior below 190 °C. In some cases, very strong particulation was detectable. No apparent correlation between the organic particulation temperature range (OPTR) and their literature thermal decomposition temperatures was evident. Efforts were made to characterize the nature of the particulates using mass spectrometry but this was hampered by the extreme complexities of the spectral patterns. In terms of their abilities to produce particulates, the diazonium compounds can be placed in four main groups reflecting their chemical composition, molecular size, and degree of substitution. Vapor phase association of the molecular fragments formed during thermal decomposition might be occurring to produce the required particulate size detectable by the present instrumentation.

The technique of Organic Particulate Thermal Analysis (OPTA) has been employed to investigate the thermal decomposition of a series of dithiocarbamate, isocyanate and cyanoethylated compounds; OPTA measures the temperature at which particulate or aerosol matter is emitted from a heated organic substance. Of the 22 compounds investigated, 15 showed strong organoparticulation activity below 200°C. With the possible exception of three compounds, no obvious correlation exists between the OPTA values and the melting or decomposition point of the compound. To explain the organoparticulation activity of these compounds, the hydrogen-bonding of polar, molecular species, present in the particulate matter, appeared necessary.

The zinc chloride-catalyzed polymerization of 2-vinylnaphthalene (VN) with both photoinitiation and electronitiation methods was examined. Good yields were obtained with both methods, the electroinitiated process being somewhat faster. The mechanism for polymerization initiation was investigated through a detailed comparison of the kinetics. Both initiation methods show a similar response to increasing input energy and to change in salt to monomer mole ratio. Both methods indicate formation of a ZnCl2–(2-VN)2 complex as intermediate with the formation of the species being rate-determining. These results, together with other similar investigations, are then used to deduce a mechanism that involves the formation of an electronically excited donor–acceptor complex. It is argued that in certain salt-stabilized, electron-delocalized, aromatic systems, such excitation is possible in electroinitiation.

To elucidate mechanisms in electroinitiated polymerization reactions a comparison was conducted between ultraviolet (UV) photoinitiation and electroinitiation of N-vinyl phthalimide with zinc chloride as a catalyst. Both methods give low yields of a complex polymer product. A detailed analysis, infrared (IR), gel permeation chromatography (GPC), elemental, and molecular weight, conducted on the polymeric products, indicated that phthalimide ring opening was occurring and that complex mixtures of poly(N-vinyl phthalimide) derivatives were formed. Both initiation methods gave comparable results, which further indicated mechanistic similarity between photo-and electroinitiation in these donor–acceptor charge transfer polymerizations.

The new technique of organoparticulate analysis has been used to investigate the thermal decomposition reactions of various types of organic compounds (i.e., metal acetylacetonates, blocked isocyanates, metal alkyldithiocarbamates, arenesulfonic acids and their amine salts). With a few exceptions, most of the compounds in these classes exhibit strong organoparticulation characteristics at temperatures below 200° as indicated by their influence on the output current of an ion chamber detector.

INTRODUCTION Previous publications in this area have described the adaptation of the new technique of organoparticulate analysis (6) (OPA), using ion chamber and condensation nuclei instrumentation, to investigate the thermal decomposition of various malonic acids (10) metal acetylacetonates (7), and diazonium compounds (8,9). We would now like to report the investigation of various areneand heterocyclic sulfonic acids and their amine salt derivatives using the same technique.

The electroinitiated preparation of equimolar copolymers of styrene and diethyl fumarate is described. The reaction medium consisted of these monomers dissolved in a methanol–zinc bromide solution. Rates of polymerization increased with increasing applied current and the copolymer yield increased linearly with the total number of Faradays transferred. The copolymer composition is 1:1 and is essentially invariant with the degree of conversion (

A comparative analysis of photoinitiation and electroinitiation can help elucidate initiation processes in donor-acceptor charge-transfer copolymerization. The technique has been applied to the zinc bromide-catalyzed copolymerization of styrene and diethyl fumarate in methanol. The photocopolymer product was analyzed by GPC, NMR, and elemental analysis. The results showed that 1:1 copolymers were formed initially, but changes occurred in both the kinetics and products after the early stages of the reaction. Significant correlations found between the two initiation methods included the initial kinetic order with respect to the initiating process and the effect on product yield of equivalent increases in total initiation energy. The limiting value of zinc bromide for both initiation methods was found to be the same. The data obtained support the contention that the copolymerization proceeds through a donor–acceptor process and that photoactivation of the preformed complex, inducing electron transfer, is a likely initiation process.

The middle ear (ME) pressure of alert and anesthetized rhesus monkeys was monitored by serial tympanograms in order to determine the gas absorption process in the ME cavity. During the four-hour observation period the ME pressure showed small, random fluctuations around zero pressure in the alert animals, whereas in the anesthetized animals, following an initial positive pressure phase, the ME pressure reached a plateau at an average pressure of − 60 mm H2O. The ME gas composition was changed by air or oxygen gas politzerization in anesthetized animals to determine the effect of different initial gas compositions on the rate of absorption of the gas and on the magnitude of ME pressure. Politzerization with air and with oxygen gas resulted in average maximum ME pressures of − 400 and − 730 mm H2O, respectively. The experimental evidence suggested that the physiological composition of ME gases is nearly that of the surrounding environment and that the rate of gas absorption is low. When the gas composition of the ME is changed, the ME pressure decreases considerably. Based on these findings, a possible mechanism for the development of negative ME pressure is proposed.

The recent studies of the anatomy of the eustachian tube and related structures in the Rhesus monkey ( Macaca mulatto) have shown that the monkey tubal system is similar to the human. This investigation in Rhesus monkeys was an attempt to verify previous studies in other animals that the tensor veli palatini muscle was the only dilator of the eustachian tube. Two unipolar stimulating electrodes were introduced into the foramen ovale, and the mandibular branch of the trigeminal nerve was electrically stimulated. Simultaneously, pressure-flow recordings through the eustachian tube were monitored. Stimulus-response relationships were obtained for five Rhesus monkeys. The degree of tubal dilation by the tensor veli palatini muscle contraction was shown to be a function of stimulating current levels. Artificially induced dilations were quite similar to the physiological dilations during swallowing when these animals were tested alert. Following complete transection of the tensor muscle, regardless of the stimulus level, no tubal dilations were observed. Stimulation of the nerve to the internal pterygoid and stimulation of the levator veli palatini muscle induced only constrictions of the tube. The tensor veli palatini muscle is the only paratubal muscle responsible for active dilation of the eustachian tube in the Rhesus monkey, and its motor innervation is the mandibular division of the trigeminal nerve.

The roles played by academicians, strategists, and physical scientists are examined in the decisions leading to an American ballistic missile defense systems. The conclusion of the study is that the expert discussion of issues influenced the form eventually assumed by the Safeguard system. However this discussion did little to influence policy makers in Congress who used parliamentary maneuvering to resolve the l969 debate.