Improving “ last-mile” public service delivery is a recurring challenge in developing countries. Could the widespread adoption of mobile phones provide scalable, cost-effective means for improvement? We use large-scale experiment to evaluate impact phone-based monitoring on program that transferred nearly billion dollars 5.7 million Indian farmers. In randomly selected jurisdictions, officials ...

This paper constructs a two-sector unified growth model. Learning-by-doing in agriculture eventually allows the preindustrial economy to leave its Malthusian trap. But entrepreneurs in the manufacturing sector do not attempt invention if not much is known about natural phenomena. This delays the industrial revolution. Since entrepreneurs identify new useful knowledge at all times in a serendipi...

We estimate the role of peer effects in technology adoption using data from a randomized distribution of menstrual cups in Nepal. Using individual randomization, we estimate causal effects of peer exposure on adoption. We find strong evidence of peer effects: two months after distribution, one additional friend with access to the menstrual cup increases usage by 18.6 percentage points. Using th...

New ideas, products, and practices take time to diffuse, a fact that is often attributed to some form of heterogeneity among potential adopters. This paper examines three broad classes of diffusion models -contagion, social influence, and social learning – and shows how to incorporate heterogeneity into each at a high level of generality without losing analytical tractability. Each type of mode...

We study a simple model of a population of agents whose interaction network co-evolves with knowledge diffusion and accumulation. Diffusion takes place along the current network and, reciprocally, network formation depends on the knowledge profile. Diffusion makes neighboring agents tend to display similar knowledge levels. On the other hand, similarity in knowledge favors network formation. Th...

This paper considers the observational implications of social influences on adoption decisions for an environment of perfect foresight adopters. We argue that social influences can produce two observable effects: (1) discontinuities in unconditional adoption curves and (2) pattern reversals in conditional adoption curves, in which earlier adoption is found for one group of actors versus another...

Within uncertain technological progress, a firm has to decide when to update its technology and select a new one among a non-decreasing range over time. Under constant return to scale, the best existing technology is implemented. Replacement is triggered not only when the firm operated technology is sufficiently obsolete but also the wedge between the latest and the state of the arts grades is ...

The business opportunities in Southern Africa have justified any effort to learn more about the phenomenon of the transfer of knowledge to the local subsidiaries. We studied four cases with activities in the industrial sector. The results obtained indicate that an efficient transfer of knowledge from the source to the recipient depends on the source’s ability to transfer this knowledge; the cli...

This paper proposes and evaluates a mechanism through which imports of unskilled intermediates (offshoring) benefit both skilled and unskilled workers by inducing capital deepening and innovation in developed countries. Data for manufacturing industries in the US over 1974-2005, show that although offshoring increases inequality between skilled and unskilled workers, unskilled workers also gain...

The paper shows that in the presence of network externalities, consumers adopt conventional technologies too early; the waiting option for a newly emerging technology is not exercised enough. This problem is aggravated when the new technology is provided by a single producer with market power because any positive value created via waiting by current consumers will be ex post appropriated by the...