We consider the problem of finding edges of a hidden weighted graph using a certain type of queries. Let G be a weighted graph with n vertices. In the most general setting, the n vertices are known and no other information about G is given. The problem is finding all edges of G and their weights using additive queries, where, for an additive query, one chooses a set of vertices and asks the sum...

BACKGROUND Recent investigations by the Ministry of Health of Cambodia suggest that counterfeit medicines have been introduced into the pharmaceutical market in tampered packaging. To further explore this possibility, an interview survey was conducted at the wholesaler level to investigate the medicinal supply chain in Cambodia. METHODS Managing executives of 62 (83.8%) registered wholesalers...

This paper considers a world of two symmetric countries with two factors and two sectors. Outputs of the two sectors are imperfect substitutes and sectors differ in relative factor intensity. Each sector contains a continuum of heterogenous firms that produce differentiated goods within their sector. Trade is costly and there are both variable and fixed costs of exporting. The paper shows that ...

Counterfeit products are internationally regarded as “the world’s second greatest public health hazards after drugs”. Counterfeiters produce counterfeit brand clothing and then sell them to consumers through unofficial channels; thus, spend a lot of money without getting the value they deserve. With rise e-shopping, safety security branded supply chains also under threat. apparel manufacturers ...

Increasing the per-unit cost of tobacco products is one of the strongest interventions for tobacco control. In jurisdictions with higher taxes in the U.S., however, cigarette pack litter studies show a substantial proportion of littered packs lack the appropriate tax stamp. More limited but still present counterfeiting also exists. We sought to examine the role of tobacco retailers as a source ...