Purchasing power parity: the choice of price index

Looking closely at the PPP argument, it states that the currencies purchasing power should not change when comparing the same basket goods across countries, and these goods should all be tradable. Hence, if PPP is valid at all, it should be captured by the relative price indices that best Öts these two features. We ran a horse race among six di§erent price indices available from the IMF database to see which one would yield higher PPP evidence, and, therefore, better Öt the two features. We used RER proxies measured as the ratio of export unit values, wholesale prices, value added deáators, unit labor costs, normalized unit labor costs and consumer prices, for a sample of 16 industrial countries, with quarterly data from 1975 to 2002. PPP was tested using both the ADF and the DFGLS unit root test of the RER series. The RER measured as WPI ratios was the one for which PPP evidence was found for the larger number of countries: six out of sixteen when we use DF-GLS test with demeaned series. The worst measure of all was the RER based on the ratio of foreign CPIs and domestic WPI. No evidence of PPP at all was found for this measure.

The impact of daycare attendance on math test scores for a cohort of 4th graders in Brazil

We estimate the impact of having attended center-based daycare institutions during early childhood on Math test scores at the 4th grade of elementary school. Because enrollment in daycare centers may depend on unobservable character-istics of the family and the child, we build and estimate a structural model of endogeneous choice of school to deal with the selectivity problem. We nd that attendance to daycare institutions is associated with a gain of approximately 0,04 standard deviation in Math test scores. This result is important to the extent our OLS results as well as most of the studies for Brazil nd no e¤ect associated to daycare attendance, suggesting selectivity may play a role on this finding.

Nature's choice? a study of the displacement of incumbents in elections

Como choques econômicos afetam eleições em democracias? Usando dados eleitorais do Congresso dos Estados Unidos, eu testo se choques adversos podem afetar desigualmente partidos incumbentes e oponentes. Esse efeito é identificado, entre vários procedimentos, por uma regressão em descontinuidade. Eu considero possibilidades teóricas para esse efeito, quando cidadãos não conseguem observar perfeitamente se a falta de bens públicos é devido a um choque adverso, ou a consumo privado do político. Quando o choque é observável, não há efeito; enquanto se não fosse, haveria. As evidências empíricas são consistentes com a teoria.

Portfolio choice with a correlated background risk : theory and evidence

We extend the static portfolio choice problem with a small background risk to the case of small partially correlated background risks. We show that respecting the theories under which risk substitution appears, except for the independence of background risk, it is perfectly rational for the individual to increase his optimal exposure to portfolio risk when risks are partially negatively correlated. Then, we test empirically the hypothesis of risk substitutability using INSEE data on French households. We find that households respond by increasing their stockholdings in response to the increase in future earnings uncertainty. This conclusion is in contradiction with results obtained in other countries. So, in light of these results, our model provides an explanation to account for the lack of empirical consensus on cross-country tests of risk substitution theory that encompasses and criticises all of them.