2015年-世界发展银行全球_Mobile_Phone_Coverage_and_Producer_Markets___Evidence_from_West_Africa_31页_298kb

Summary of "Mobile Phone Coverage and Producer Markets: Evidence from West Africa"

Core Content

This paper investigates the impact of mobile phone coverage on producer price dispersion in agricultural markets in Niger, focusing on three commodities: cowpea, millet, and sorghum. The study builds on previous research by Aker (2010) and explores how improved access to information through mobile phones affects market efficiency, particularly in producer markets.

Main Viewpoints

• Mobile phone coverage has expanded significantly in sub-Saharan Africa, especially in Niger, where it was introduced in 2001 and reached 90% of agricultural markets by 2008.
• Price information plays a crucial role in arbitrage behavior and market efficiency. In developed countries, access to such information has improved, but in sub-Saharan Africa, it was historically costly and limited due to infrastructure constraints.
• Mobile phones reduce the cost of obtaining price information, particularly for traders who are more likely to adopt them than farmers. This allows traders to make more informed decisions and potentially increase spatial arbitrage, leading to reduced price dispersion.

Key Findings

• Cowpea (a semi-perishable commodity) shows a 6% reduction in spatial producer price dispersion with mobile phone coverage. The effects are most pronounced in remote markets and during certain times of the year.
• Millet and sorghum (staple grains with lower perishability) do not show any significant impact from mobile phone coverage on producer price dispersion or price levels.
• Mobile phone coverage is associated with a 6% reduction in intra-annual price variation for cowpea, suggesting that it helps stabilize prices over time.
• Farmers are not significantly affected by mobile phone coverage in terms of their marketing behavior or sales prices, which is consistent with earlier studies (Fafchamps and Minten 2012; Aker and Ksoll 2013).
• The introduction of mobile phone coverage enables traders to better coordinate their activities and respond to local market conditions, which in turn affects price dispersion.

Theoretical Predictions

• The paper presents a model where mobile phone coverage acts as an informative signal for traders, allowing them to:
  1. Shift their attention to surplus markets with better information.
  2. Raise prices in surplus (low price) markets and lower prices in deficit (high price) markets.
  3. Reduce spatial price dispersion between markets with mobile phone coverage.
• These effects are stronger for perishable and semi-perishable commodities, where intertemporal arbitrage is less effective.
• For storable commodities, the effects of mobile phone coverage on price dispersion may be less pronounced due to the ability of farmers to store goods and smooth prices over time.

Contributions

• The paper contributes to the economic literature on the role of information in market efficiency by:
  • Showing that mobile phone coverage has a significant impact on producer price dispersion for semi-perishable commodities like cowpea.
  • Providing empirical evidence on the differential effects of mobile phone coverage across perishable and non-perishable commodities.
• It also extends previous studies by examining the long-term impact of mobile phone coverage on multiple commodities over a 10-year period.

Data and Methodology

• The study uses market-level panel data from 37 markets in Niger between 1999 and 2008, collected by the Agricultural Market Information Service (AMIS).
• It also incorporates survey data from traders and farmers in 32 markets and 37 villages across six regions of Niger, conducted between 2005 and 2007.
• A 2009 survey of 1,038 farm households from 100 villages provides additional insights into the relationship between mobile phone coverage and farmers' behavior.
• The empirical strategy involves analyzing price dispersion and price variation over time and space, controlling for factors like fuel prices, transport costs, rainfall, and road quality.

Conclusion

The paper concludes that mobile phone coverage has a positive impact on market efficiency in producer markets, particularly for semi-perishable commodities. The findings suggest that improved information access can lead to more efficient price formation and reduced spatial price dispersion. However, the effects are limited for non-perishable commodities and consumer markets, highlighting the importance of commodity characteristics in determining the impact of information technology on market outcomes.