Testing for Stock Market Integration in a Developing Economy: Colombia

This paper examines the linkage between two parallel stock exchanges trading the same shares in Colombia, namely the Bogotá Stock Exchange and the Medellín Stock Exchange. We provide empirical evidence to support the hypothesis that these two markets can be best described as fully integrated over a period of almost four decades, which is consistent with the view that arbitrage opportunities are only possible in the short but not in the long run. In addition, we find evide

Testing the law of one price in food markets: evidence for Colombia using disaggregated data

This paper applies stationarity tests to examine evidence of market integration for a relatively large sample of food products in Colombia. We Önd little support for market integration when using the univariate KPSS tests for stationarity. However, within a panel context and after allowing for cross sectional dependence, the Hadri tests provide much more evidence supporting the view that food markets are integrated or, in other words, that the law of one price holds for most products.

Genetic testing with primary prevention and moral hazard

We develop a model where a free genetic test reveals whether the individual tested has a low or high probability of developing a disease. A costly prevention effort allows high-risk agents to decrease the probability of developing the disease. Agents are not obliged to take the test, but must disclose its results to insurers. Insurers offer separating contracts which take into account the individual risk, so that taking the test is associated to a discrimination risk. We study the individual decisions to take the test and to undertake the prevention effort as a function of the effort cost and of its e¢ ciency. We obtain that, if effort is observable by insurers, agents undertake the test only if the effort cost is neither too large nor too low. If the effort cost is not observable by insurers, they face a moral hazard problem which induces them to under-provide insurance. We obtain the counterintuitive result that moral hazard increases the value of the test if the effort cost is low enough. Also, agents may perform the test for lower levels of prevention e¢ ciency when effort is not observable

Resultados de la cirugía laparoscópica comparada con la cirugía abierta en el cáncer colorrectal. Revisión sistemática

Determinar el efecto de la cirugía laparoscópica versus cirugía abierta sobre la supervivencia en el manejo de pacientes del cáncer colorectal.