Improving Lexical Choice in Neural Machine Translation

We explore two solutions to the problem of mistranslating rare words in neural machine translation. First, we argue that the standard output layer, which computes the inner product of a vector representing the context with all possible output word embeddings, rewards frequent words disproportionately, and we propose to fix the norms of both vectors to a constant value. Second, we integrate a simple lexical module which is jointly trained with the rest of the model. We evaluate our approaches on eight language pairs with data sizes ranging from 100k to 8M words, and achieve improvements of up to +4.3 BLEU, surpassing phrase-based translation in nearly all settings.Comment: Accepted at NAACL HLT 201

Do natural disasters open a window of opportunity for corruption?

This study explores the link between natural disasters and corruption at the local government. We examine whether a natural disaster affects official households more favorably than non-official households. We find that natural disasters decrease nonofficial household expenditures significantly, however have negligible effect on official household expenditures. Meanwhile, both kinds of households experience similar reduction in incomes, and have much the same disaster coping strategies. Together, the results imply that local officials may receive unobserved monetary compensation – we define as corruption - in the aftermath of natural disasters

Does nurture matter: theory and experimental investigation on the effect of working environment on risk and time preferences

Building upon the reference dependent preferences model, we develop a theoretical framework to examine the relationship between environment and preferences. To verify the model’s prediction, we use a combined artefactual field experiment and household survey data in Vietnam to investigate whether involvement is risky and has long-run targeted benefits, thereby causing fishermen to exhibit different risk and time preferences than workers in other occupations. Using a structural model approach, we integrate prospect theory and hyperbolic time discounting into a single framework, to simultaneously estimate and correlate the parameters of both risk and time preferences with other demographic variables. The key finding that fishermen are found to be less risk-averse and more patient than others asserts the theoretical prediction about the influence of the working environment on preferences

Linking loss aversion and present bias with overspending behaviour of tourists: insights from a lab-in-the-field experiment

Building upon Prospect Theory and Hyperbolic Time Discounting models, we explore how behavioral factors influence the probability of overspending among outbound leisure travelers. We construct our data in two steps. First, we collect demographics and travel-related variables from a random sample of 314 Singaporean tourists across different age groups and income levels. Second, we conduct a field experiment to measure their risk and time preferences, specifically loss aversion and present bias. We then explore the link between the measured preferences to overspending behaviour. The findings reveal an interesting link between loss aversion, present bias and traveling expenditure patterns: outbound tourists with high loss aversion and high present bias are more likely to overspend. Finally, our study also highlights the role of group identity in de-biasing. Specifically, individuals are more likely to behave according to standard economic models when making decisions in groups

Eigenfilters: A new approach to least-squares FIR filter design and applications including Nyquist filters

A new method of designing linear-phase FIR filters is proposed by minimizing a quadratic measure of the error in the passband and stopband. The method is based on the computation of an eigenvector of an appropriate real, symmetric, and positive-definite matrix. The proposed design procedure is general enough to incorporate both time- and frequency-domain constraints. For example, Nyquist filters can be easily designed using this approach. The design time for the new method is comparable to that of Remez exchange techniques. The passband and stopband errors in the frequency domain can be made equiripple by an iterative process, which involves feeding back the approximation error at each iteration. Several numerical design examples and comparisons to existing methods are presented, which demonstrate the usefulness of the present approach