This study tests the importance of Ricardian technology differences for international trade. The empirical analysis has three comparative advantages: including emerging and advanced economies, isolating panel variation regarding the link between productivity and exports, and exploiting...

We describe how and why Magnetic Resource Imaging (MRI) came to complement – and partially replace -- computed tomography (CT) imaging of soft tissue. Specifically we chronicle: 1) the development of foundational techniques and prototypes (through the 1970s); 2) initial commercialization and...

We describe how the development of x-ray-based techniques and equipment (“mammography”) lead to widespread screening for breast cancer and enabled “minimally invasive” biopsies of breast tumors. Specifically, we chronicle how: 1) new protocols and equipment catalyzed the first widespread...

We describe how efforts on multiple fronts, including advocacy, training and technological development made ultrasound the second most commonly used diagnostic imaging technology (after X-rays). Specifically, we chronicle: 1) ultrasound's development and introduction in the 1950s and 1960s; 2)...

We describe how Computed Tomography (CT) scanners - that combine x-rays and computers to image soft tissues of the brain and other organs -- have become a widely used diagnostic tool. Specifically, we chronicle the: 1) development of the first CT scanner (through the early-1970s); 2) rapid and...

We describe how a diverse cast of characters including public health organizations, research laboratories, for-profit health care companies, activists and regulators, rolled back the outbreak of HIV/AIDS in just fifteen years. Moreover, as the case history shows, a stunning reduction in deaths...