A refined version of general E-unification

Transformation--based systems for general E-unification were first investigated by Gallier and Snyder. Their system extends the well--known rules for syntactic unification by Lazy Paramodulation, thus coping with the equational theory. More recently, Dougherty and Johann improved on this method by giving a restriction of the Lazy Paramodulation inferences. In this paper, we show that their system can be further improved by a stronger restriction on the applicability of Lazy Paramodulation. It turns out that the framework of proof transformations provides an elegant and natural means for proving completeness of the inference system

Are remittances a substitute for credit? Carrying the financial burden of health shocks in national and transnational households

The assumption that remittances are a substitute for credit has been an implicit or explicit theoretical foundation of many empirical studies on remittances. This paper directly tests this assumption by comparing the response to health-related shocks among national and transnational households using panel data from Mexico for 2002 and 2005. While the occurrence of serious health shocks that required hospital treatment doubled the average debt burden of exposed households compared to the control group, households with nuclear family members (a parent, child, or spouse) in the US did not increase their debts due to health shocks. This finding is consistent with the view that remittances respond to households' demand for financing emergencies and make them less reliant on debt-financing

Policy Constraints and the Recovery from Banking Crises

While much research has been done on causes and effects of banking crises, little is know about what determines recovery from banking crises, despite of large variations in post-crises performances across countries. In order to identify factors that determine the length of recovery (e.g. the time it takes until countries reach their pre-crisis level of per capita GDP), this paper employs event history analysis on 138 incidents of banking crises between 1970 and 2013. Cox Proportional Hazards show that both domestic and external constraints play a key role for recovering from banking crises. In particular, countries that suffered from simultaneous currency crises as well as those with overvalued currencies tended to recover later. Regarding external factors, a low growth of world trade has a negative effect on recovery, and so does uncertainty in financial markets as reflected in high gold prices. Moreover, contractionary monetary policy of the US Fed as Central Bank of the international key currency has a negative effect on the length of recovery in emerging markets and developing countries with open capital accounts. The latter empirical relationship reflects the vulnerability of developing countries and emerging markets to policies in the global financial centers and points to the necessity of understanding crises policies as embedded within monetary asymmetries that significantly limit the policy space of countries at the lower ends of the global currency hierarchy

Evidence from Mexican household data

In policy discussions, it has frequently been claimed that migrants’ remittances could function as a ‘catalyst’ for financial access among receiving households. This paper provides empirical evidence on this hypothesis from Mexico, a major receiver of remittances worldwide. Using the Mexican Family Life Survey panel (MxFLS) for 2002 and 2005, the results from the fixed effects logit model show that receiving remittances is strongly correlated with the ownership of savings accounts and, to some degree, with the availability of borrowing options. These effects are more important for rural households than for urban households and are more important for microfinance institutions, than for traditional banks

Deportations and the Roots of Gang Violence in Central America

El Salvador, Honduras and Guatemala count among today’s most violent countries of the world. Qualitative research has claimed that large-scale deportations of Central American convicts have played an important role for the spread of gangs and rampant violence in the region. Using a novel identification strategy, this paper provides the first econometric evidence for this hypothesis from the case of El Salvador. Regarding the dependent variable, the policy experiment of a truce between rivaling gangs in 2012 allows to single out gang-related killings from overall homicide rates. The explanatory variable exploits subnational variation in the exposure of migrant communities to exogenous conditions in the host country. Violence spilled over to migrants’ places of origin when migrant corridors developed around US destinations with high pre-existing levels of violent crime. The cross-sectional evidence is backed by panel data analysis dating back to 1999. The annual inflow of convicts translated into rising homicides mainly in those municipalities whose migrants were exposed to high pre-existing crime at destination, whereas deportations of non-convicts did not have the same effect. These finding are in line with evidence on the origin of Central American gangs in US cities and convicts’ return to their places of birth after massive deportations since the mid-1990s

Semi-unification

Semi-unifiability is a generalization of both unification and matching. It is used to check nontermination of rewrite rules. In this paper an inference system is presented that decides semi-unifiability of two terms s and t and computes a semi-unifier. In contrast to an algorithm by Kapur, Musser et al, this inference system comes very close to the one for ordinary unification

Why Foreclosure Rates in African American Neighborhoods are so High: Looking at the Real Reaonss

Foreclosures have become one of the most important urban problems faced by contemporary cities. Our goal is to better understand factors that affect foreclosure rates in a typical, mid-sized U.S. city. While previous research has found that a key explanatory variable positively affecting foreclosures is the percentage of minorities in a neighborhood, our model finds that the effect of percent non-white is impacted by several key intervening variables, such as the presence and proximity of EPA listed Super-Fund Sites along with walkability, in these majority black neighborhoods. In the past, these factors have been ignored by social scientists because they are difficult to measure. Firstly, we look at how speculators in majority black neighborhoods account for a significant share of foreclosures in these neighborhoods. Secondly, we examine the effect of EPA-listed Superfund Sites and find that in this instance almost all are located either near or within many of these majority black neighborhoods and finally we look at walkability and its effect on foreclosures. We find that these three variables help explain the causes of greater foreclosures occurring in majority black neighborhoods. These three key variables add to previous explanations of high foreclosures resulting from unfavorable loan terms offered in black neighborhoods.

Do Remittances Increase Borrowing?

While recent literature has pointed out that migrants’ remittances have a positive impact on savings with financial institutions, findings with respect to access to and the use of loans have been ambiguous. This paper investigates whether the reception of remittances facilitates taking up loans from formal or informal sources among Mexican households and finds positive and statistically significant effects of remittances on borrowing and on the existence of debts. We address methodological concerns of selection bias and reverse causality through household fixed effects and an instrumental strategy that exploits distance to train lines and labor market conditions in the US as exogenous determinants of remittances

Are Remittances a 'Catalyst' for Financial Access? Evidence from Mexico

In policy discussions, it has frequently been claimed that migrants' remittances could function as a 'catalyst' for financial access among receiving households. This paper provides empirical evidence on this hypothesis from Mexico, a main receiver of remittances worldwide. Using the Mexican Family Life Survey panel (MxFLS) for 2002 and 2005, the results from the treatment-effect-model at household level show that a change in remittance status has an important impact on ownership of savings accounts and the availability of borrowing options. This effect is significant for rural, but not for urban households and important for microfinance institutions, but not for traditional banks