Spin-Orbit Misalignment of Merging Black-Hole Binaries with Tertiary Companions

We study the effect of external companion on the orbital and spin evolution of merging black-hole (BH) binaries. An sufficiently close by and inclined companion can excite Lidov-Kozai (LK) eccentricity oscillations in the binary, thereby shortening its merger time. During such LK-enhanced orbital decay, the spin axis of the BH generally exhibits chaotic evolution, leading to a wide range ($0^\circ$-$180^\circ$) of final spin-orbit misalignment angle from an initially aligned configuration. For systems that do not experience eccentricity excitation, only modest ($\lesssim 20^\circ$) spin-orbit misalignment can be produced, and we derive an analytic expression for the final misalignment using the principle of adiabatic invariance. The spin-orbit misalignment directly impacts the gravitational waveform, and can be used to constrain the formation scenarios of BH binaries and dynamical influences of external companions.Comment: Published in ApJ

CT Image Reconstruction by Spatial-Radon Domain Data-Driven Tight Frame Regularization

This paper proposes a spatial-Radon domain CT image reconstruction model based on data-driven tight frames (SRD-DDTF). The proposed SRD-DDTF model combines the idea of joint image and Radon domain inpainting model of \cite{Dong2013X} and that of the data-driven tight frames for image denoising \cite{cai2014data}. It is different from existing models in that both CT image and its corresponding high quality projection image are reconstructed simultaneously using sparsity priors by tight frames that are adaptively learned from the data to provide optimal sparse approximations. An alternative minimization algorithm is designed to solve the proposed model which is nonsmooth and nonconvex. Convergence analysis of the algorithm is provided. Numerical experiments showed that the SRD-DDTF model is superior to the model by \cite{Dong2013X} especially in recovering some subtle structures in the images

The Consequences of Corruption: Evidence from China

With complementary Chinese data sets and alternative corruption measures, we explore the consequences of corruption. Adopting a novel approach we provide evidence that corruption can have both, positive and negative effects, on economic development. The overall impact of corruption might be the balance of the two simultaneous effects within a specific institutional environment (“grease the wheels” and “sand the wheels”). Corruption is observed to considerably increase income inequality in China. We also find that corruption strongly reduces tax revenue. Looking at things from an expenditure point of view we observe that corruption significantly decreases government spending on education, R&D and public health in China. We also observe that regional corruption significantly reduces inbound foreign direct investment in Chinese regions, which indicates that the pollution haven hypothesis may not hold in China. This finding sheds a new light on the “China puzzle” that China is the largest developing host of FDI while it is appears to be very corrupt. Finally we observe that corruption substantially aggravates pollution probably through loosening environment regulation, and that it modifies the effects of trade openness and FDI on the stringency of environmental policy in a manner opposite to that observed in literature to date.Corruption, China, Government, Economic Development, Inequality, Environment

When the Cat's Away, the Mice Will Play: Gambling Behaviour of Visitors in Australia

What happens if national legal laws or enforcements and social norms are no longer able to directly regulate individual behaviour? According to our knowledge, not much empirical evidence has emerged answering such a seemingly simple question. The challenge is to distinguish between the effects of social norm and of legal enforcement. One way to explore such a question in an almost natural quasi-experimental setting is to focus on tourists’ behaviour. Tourists are visiting another country for a relatively short period of time and are acting in a different (legal) environment where formal and informal rules are different to those found in their own country. Using data from Australia we focus on gambling activities since these are prohibited in some countries. We find that tourists from countries where gambling is prohibited spend a significantly larger share of their entertainment expenditure on gambling than those who come from countries where gambling is legalized. Thus, gambling increases (“mice playâ€) without legal enforcement (“when the cat is awayâ€). It is also noteworthy that there seems to be a lack of internalized social norms that would prevent tourists from partaking in these gambling activities.gambling, legal enforcement, social norms

Democracy, Property Rights, Income Equality, and Corruption

This paper presents theoretical and empirical evidence on the nexus between corruption and democracy. We establish a political economy model where the effect of democracy on corruption is conditional on income distribution and property rights protection. Our empirical analysis with cross-national panel data provides evidence that is consistent with the theoretical prediction. Moreover, the effect of democratization on corruption depends on the protection of property rights and income equality which shows that corruption is a nonlinear function of these variables. The results indicate that democracy will work better as a control of corruption if the property rights system works and there is a low level of income inequality. On the other hand if property rights are not secured and there is strong income inequality, democracy may even lead to an increase of corruption. In addition, property rights protection and the mitigation of income inequality contribute in a strong manner to the reduction of corruption.Corruption, Democracy, Income inequality, Property rights

The Consequences of Corruption: Evidence from China

With complementary Chinese data sets and alternative corruption measures, we explore the consequences of corruption. Adopting a novel approach we provide evidence that corruption can have both, positive and negative effects, on economic development. The overall impact of corruption might be the balance of the two simultaneous effects within a specific institutional environment (“grease the wheels†and “sand the wheelsâ€). Corruption is observed to considerably increase income inequality in China. We also find that corruption strongly reduces tax revenue. Looking at things from an expenditure point of view we observe that corruption significantly decreases government spending on education, R&D and public health in China. We also observe that regional corruption significantly reduces inbound foreign direct investment in Chinese regions, which indicates that the pollution haven hypothesis may not hold in China. This finding sheds a new light on the “China puzzle†that China is the largest developing host of FDI while it is appears to be very corrupt. Finally we observe that corruption substantially aggravates pollution probably through loosening environment regulation, and that it modifies the effects of trade openness and FDI on the stringency of environmental policy in a manner opposite to that observed in literature to date.Corruption; China; Government; Economic Development; Inequality;

Corruption and Political Interest: Empirical Evidence at the Micro Level

The topic of corruption has recently attracted a great deal of attention, yet there is still a lack of micro level empirical evidence regarding the determinants of corruption. Furthermore, the present literature has not investigated the effects of political interest on corruption despite the interesting potential of this link. We address these deficiencies by analyzing a cross-section of individuals, using the World Values Survey. We explore the determinants of corruption through two dependent variables (perceived corruption and the justifiability of corruption). The impact of political interest on corruption is explored through three different proxies, presenting empirical evidence at both the cross-country level and the within-country level. The results of the multivariate analysis suggest that political interest has an impact on corruption controlling for a large number of factors.Corruption; Political Interest, Social Norms

Corruption and Political Interest: Empirical Evidence at the Micro Level

The topic of corruption has recently attracted a great deal of attention, yet there is still a lack of micro level empirical evidence regarding the determinants of corruption. Furthermore, the present literature has not investigated the effects of political interest on corruption despite the interesting potential of this link. We address these deficiencies by analyzing a cross-section of individuals, using the World Values Survey. We explore the determinants of corruption through two dependent variables (perceived corruption and the justifiability of corruption). The impact of political interest on corruption is explored through three different proxies, presenting empirical evidence at both the cross-country level and the within-country level. The results of the multivariate analysis suggest that political interest has an impact on corruption controlling for a large number of factors.Corruption, Political Interest, Social Norms

The Causes of Corruption: Evidence from China

In this study we explore in detail the causes of corruption in China using two different sets of data at the regional level (provinces and cities). We observe that regions with more anti-corruption efforts, histories of British rule, higher openness, more access to media and relatively higher wages of government employees are markedly less corrupt; while social heterogeneity, regulation, abundance of resource and state-owned enterprises substantially breed regional corruption. Moreover, fiscal decentralization is discovered to depress corruption significantly, while administrative decentralization fosters local corruption. We also find that there is currently a positive relationship between corruption and economic development in China that is mainly driven by the transition to a market economy.Corruption; China; Government; Decentralization; Deterrence; Social Heterogenity

Corruption and Social Interaction: Evidence from China

We explore theoretically and empirically whether social interaction, including local and global interaction, influences the incidence of corruption. We first present an interaction-based model on corruption that predicts that the level of corruption is positively associated with social interaction. Then we empirically verify the theoretical prediction using within-country evidence at the province-level in China during 1998 to 2007. Panel data evidence clearly indicates that social interaction has a statistically significantly positive effect on the corruption rate in China. Our findings, therefore, underscore the relevance of social interaction in understanding corruption.Corruption, Social Interaction, China