doi:10.2471/BLT07.049510 In 1985, Karel Styblo derived one of the guiding rules of tuberculosis (TB) epidemiology. Bringing together data from 16 countries, he proposed that an annual incidence of 50 sputum-smearpositive TB cases in a population of 100 000 generates an annual risk of infection of 1%.1 This rule of thumb quickly became an established and cherished part of the epidemiological can...

The main goal of this paper is to investigate the relation between the meaning of a sentence and its truth conditions. We report on a comprehension experiment on counterfactual conditionals, based on a context in which a light is controlled by two switches. Our main finding is that the truth-conditionally equivalent clauses (i) switch A or switch B is down and (ii) switch A and switch B are not...

Telecommunications is a trillion-dollar industry undergoing a massive transformation, both in its technological underpinnings and its market dynamics. As technology and market developments undermine longstanding business models and value chains, existing legal frameworks are failing. A ‘‘layered’’ model for communications policy would provide a better foundation for competition, investment, and...

We experimentally investigate the extent to which social observability of one’s actions and the possibility of social non-monetary judgment affect the decision to engage in rule breaking behavior. We consider three rule breaking scenarios — theft, bribery and embezzlement — in the absence of any formal enforcement mechanism. By involving a student sample characterized by cultural heterogeneity ...