Tax return as a political statement

The accuracy of a tax return is usually interpreted as an outcome of the tax evasion decision by an individual. However, in non-democratic regimes with predatory blackmail tax systems it is possible that large sums voluntarily reported by influential politicians or businessmen may be used as political statements. By openly acknowledging one's personal income an individual can signal the strength of one's position, or, on the contrary, the submissiveness to the political leadership. In this paper we explore the idea of the tax return as a political statement and test it using a unique dataset of the tax returns filed by the Russian regional governors and the members of their families for the year 2009. Our results conjecture that Russian governors may deliberately file their tax return as a political statement to signal their strength vis-à-vis the central government. --tax compliance,communication in non-democracies,Russian regions

Cascade Freezing of Supercooled Water Droplet Collectives

Surface icing affects the safety and performance of numerous processes in technology. Previous studies mostly investigated freezing of individual droplets. The interaction among multiple droplets during freezing is investigated less, especially on nanotextured icephobic surfaces, despite its practical importance as water droplets never appear in isolation, but in groups. Here we show that freezing of a supercooled droplet leads to spontaneous self-heating and induces strong vaporization. The resulting, rapidly propagating vapor front causes immediate cascading freezing of neighboring supercooled droplets upon reaching them. We put forth the explanation that, as the vapor approaches cold neighboring droplets, it can lead to local supersaturation and formation of airborne microscopic ice crystals, which act as freezing nucleation sites. The sequential triggering and propagation of this mechanism results in the rapid freezing of an entire droplet ensemble resulting in ice coverage of the nanotextured surface. Although cascade freezing is observed in a low-pressure environment, it introduces an unexpected pathway of freezing propagation that can be crucial for the performance of rationally designed icephobic surfaces

Essays on Beliefs and Economic Behavior

Next to preferences over outcomes, people's subjective beliefs about unobserved states of the world are the central building block of economic models of decision-making. This thesis submits that a more nuanced account of the nature of subjective beliefs can improve the explanatory power of models of economic behavior. It revolves around the following questions. How do people incorporate new information into their beliefs? What are the cognitive mechanisms underlying different updating rules? To what extent is observed heterogeneity in beliefs and behavior predictable? Are beliefs shaped by people's individual experience? How do beliefs translate into economic behavior? The unifying approach of this work is cross-disciplinary, leveraging ideas from other fields such as cognitive science and psychology. The empirical motivation for Chapter 2: "Inattentive Inference" is the pervasive evidence for miscalibration to news in practice. In many situations, beliefs overreact, as if base rates are neglected or new information overweighted, and they often underreact, leading to information rigidities or conservatism in updating. Whether and how these conflicting updating patterns can be reconciled remains an open question. Chapter 2 builds on the observation that most information structures pose a signal extraction problem for belief updating: an agent wants to learn an unobserved state of the world X, but information about X is "compound" in that it also depends on other states Y. Inattention to other causes Y in the signal structure could create misattribution to X. A series of laboratory and online experiments show that most people do not take into account other causes (labelled feature neglect), leading to excessively sensitive and overprecise beliefs. There is pronounced heterogeneity, with up to 90% of beliefs corresponding to three updating rules: feature neglect, Bayesian updating and non-updates. Exploring the underlying mechanism, I find that unawareness about the necessity to factor in alternative causes drives feature neglect, whereas non-updating follows cost-benefit considerations. I propose a conceptual framework that accounts for the combined evidence. Moreover, learning is found to be limited by unawareness, but cues and hints debias by changing people's mental models directly. Chapter 3: "Heterogeneity of Loss Aversion and Expectations-Based Reference Points" examines how people's forward-looking beliefs, i.e., expectations, affect their decisions. A seminal insight from psychology is that we tend to evaluate outcomes relative to a reference point. In theories of reference-dependent decision-making, people code outcomes as gains or losses relative to some reference point. Yet, the location of this reference point is a critical degree of freedom. A recent theoretical advance characterizes the reference point based on people's expectations about their own future outcomes. In the past decade, empirical tests of this model yielded mixed results and there remains a lack of consensus on the location – and thus the empirical relevance – of reference points. Chapter 3 attempts to reconcile different approaches and findings. In this study that is joint work with Lorenz Goette, Charles Sprenger and Alexandre Kellogg, we developed a tightly controlled exchange experiment with two main innovations: First, the design recognizes that testing the role of expectations-based reference points requires experimental control of other plausible avenues of reference dependence, such as the status quo or personal experience. Second, it accommodates a critical confound related to the key behavioral parameter, loss aversion. Loss aversion captures that people dislike losses more than equal-sized gains. A growing body of evidence documents substantial heterogeneity in measured levels of loss aversion, with a substantial fraction of people being loss-neutral or even loss-loving. Different levels of loss aversion, however, lead to different signs of comparative statics. In our results, recognizing heterogeneity in loss aversion allowed us to reliably recover the central prediction of expectations-based reference points. Chapter 4: "Breaking Trust: On the Persistent Effect of Economic Crisis Experience" shifts the focus to a particularly important belief for economic transactions. Trust is the degree of belief in the benevolent intentions of another person. In the realm of economic behavior, trust plays a central role as a prerequisite for all forms of economic exchange: without a minimal amount of trust in the counterpart, no person would be willing to sign a contract. In fact, trust has been shown to affect economic outcomes at the individual, group and societal levels. However, much less is known about the origins of trust. Recent evidence documents that levels of trust vary substantially across locations and over time, but the determinants of this geographical and temporal variation are not well understood. In Chapter 4, which is joint work with Tom Zimmermann, we analyzed the economic implications of a breach of trust argument, positing that trust is not easily restored once it has been abused. Building on a nascent literature on the economic implications of people's lifetime experience, we hypothesized that trust is partially determined by the experience of catastrophic macroeconomic events. Using a variety of identification strategies in a large cross-country sample, we estimated a persistent and robust negative long-term effect of economic crisis experience on trust in other people. In line with the breach of trust hypothesis, the effect was specific to living through crises in trust- intensive domains, most of all banking crises. The effect was not driven by distrust in financial institutions but was accommodated by a lack of confidence in the political class, and operated via beliefs rather than changes in preferences. Chapter 5: "Negative Long-run Effects of Prosocial Behavior on Happiness" studies happiness. In recent times, measures of subjective well-being are increasingly viewed as relevant indicators of a society's welfare, and a rising number of countries have incorporated national happiness levels as a policy objective. This development concurs with a renewed scientific interest in the causes of happiness. Most prominently, recent studies contribute to a debate spanning more than two millennia on the hypothesis that prosocial behavior is a key to happiness. The existing causal evidence indeed confirms a positive influence of prosocial behavior on happiness, but is limited to the short-term effects of an enforced prosocial or selfish act. In Chapter 5, which is joint work with Armin Falk, we reconsider this hypothesis in a behavioral experiment that extends the scope of previous studies in various dimensions. In our Saving a Life paradigm, every participant either saved one human life in expectation or received one hundred euros, respectively. Using a choice between two binary lotteries with different chances of saving a life, we observed subjects' intentions at the same time as creating random variation in prosocial outcomes. We repeatedly measured happiness at different time horizons after the experiment. We confirmed the previous consensus finding of a positive short-term effect, but this effect quickly faded. As time passed, the sign of the effect even reversed, and we recorded significantly greater happiness associated with the selfish outcome than with the prosocial outcome one month later. Our findings hint at distinct sources of happiness as time passes. Chapter 5 provides a first piece of evidence that a comprehensive understanding of the effects of prosocial behavior on happiness requires a more nuanced view that accounts for delayed effects

A linear mixed model approach to gene expression-tumor aneuploidy association studies.

Aneuploidy, defined as abnormal chromosome number or somatic DNA copy number, is a characteristic of many aggressive tumors and is thought to drive tumorigenesis. Gene expression-aneuploidy association studies have previously been conducted to explore cellular mechanisms associated with aneuploidy. However, in an observational setting, gene expression is influenced by many factors that can act as confounders between gene expression and aneuploidy, leading to spurious correlations between the two variables. These factors include known confounders such as sample purity or batch effect, as well as gene co-regulation which induces correlations between the expression of causal genes and non-causal genes. We use a linear mixed-effects model (LMM) to account for confounding effects of tumor purity and gene co-regulation on gene expression-aneuploidy associations. When applied to patient tumor data across diverse tumor types, we observe that the LMM both accounts for the impact of purity on aneuploidy measurements and identifies a new association between histone gene expression and aneuploidy

Asparagine promotes cancer cell proliferation through use as an amino acid exchange factor.

Cellular amino acid uptake is critical for mTOR complex 1 (mTORC1) activation and cell proliferation. However, the regulation of amino acid uptake is not well-understood. Here we describe a role for asparagine as an amino acid exchange factor: intracellular asparagine exchanges with extracellular amino acids. Through asparagine synthetase knockdown and altering of media asparagine concentrations, we show that intracellular asparagine levels regulate uptake of amino acids, especially serine, arginine and histidine. Through its exchange factor role, asparagine regulates mTORC1 activity and protein synthesis. In addition, we show that asparagine regulation of serine uptake influences serine metabolism and nucleotide synthesis, suggesting that asparagine is involved in coordinating protein and nucleotide synthesis. Finally, we show that maintenance of intracellular asparagine levels is critical for cancer cell growth. Collectively, our results indicate that asparagine is an important regulator of cancer cell amino acid homeostasis, anabolic metabolism and proliferation

Heterogeneity of Loss Aversion and Expectations-Based Reference Points

This project examines the role of heterogeneity in loss aversion for identifying models of expectations-based reference dependence (Kőszegi and Rabin, 2006, 2007) (KR). Different levels of loss aversion lead to different signs for comparative statics previously used to test the KR model. In an experiment with 607 subjects, we show heterogeneous treatment effects over loss aversion types. Recognizing heterogeneity in loss aversion allows us to reliably recover the KR model’s central element of expectations-based reference points. Additional effects are discussed related to the subjective perception of exchange experiences

Heterogeneity of Loss Aversion and Expectations-Based Reference Points

This project examines the role of heterogeneity in loss aversion for identifying models of expectations-based reference dependence (Kőszegi and Rabin, 2006, 2007) (KR). Different levels of loss aversion lead to different signs for comparative statics previously used to test the KR model. In an experiment with 607 subjects, we show heterogeneous treatment effects over loss aversion types. Recognizing heterogeneity in loss aversion allows us to reliably recover the KR model’s central element of expectations-based reference points. Additional effects are discussed related to the subjective perception of exchange experiences

Heterogeneity of Gain-Loss Attitudes and Expectations-Based Reference Points

This project examines the role of heterogeneity in gain-loss attitudes for identifying models of expectations-based reference dependence (Koszegi and Rabin, 2006, 2007) (KR). Different gain-loss attitudes lead to different signs for KR comparative statics. Failure to account for the known heterogeneity in gain-loss attitudes is a central confounding factor challenging prior tests of the KR model conducted under the assumption of universal loss aversion. We document heterogeneous treatment effects over gain-loss types in both an initial experiment and an exact replication. Recognizing heterogeneity over types allows us to both recover the KR model’s central predictions, and account for inconsistency across prior empirical tests

Measuring the scientific effectiveness of contact tracing : evidence from a natural experiment

Contact tracing has for decades been a cornerstone of the public health approach to epidemics, including Ebola, severe acute respiratory syndrome, and now COVID-19. It has not yet been possible, however, to causally assess the method’s effectiveness using a randomized controlled trial of the sort familiar throughout other areas of science. This study provides evidence that comes close to that ideal. It exploits a large-scale natural experiment that occurred by accident in England in late September 2020. Because of a coding error involving spreadsheet data used by the health authorities, a total of 15,841 COVID-19 cases (around 20% of all cases) failed to have timely contact tracing. By chance, some areas of England were much more severely affected than others. This study finds that the random breakdown of contact tracing led to more illness and death. Conservative causal estimates imply that, relative to cases that were initially missed by the contact tracing system, cases subject to proper contact tracing were associated with a reduction in subsequent new infections of 63% and a reduction insubsequent COVID-19–related deaths of 66% across the 6 wk following the data glitch