IDEAS home Printed from
   My bibliography  Save this paper

Integration and Equilibrium of Maize Markets in Southern Africa: A SADC Sub-regional Assessment


  • Mutambatsere, Emelly
  • Mabaya, Edward T.
  • Christy, Ralph D.


This paper investigates the spatial integration and efficiency between five central markets in southern Africa. The study uses data on commodity prices, trade flows, and transfer costs from central maize markets in Botswana, Malawi, and South Africa, and two in Mozambique, analyzed using the Parity Bounds Model, the Barrett-Li Model and some level 1 and non-parametric assessments. The study seeks to (1) evaluate the nature of price and trade relations, (2) establish the level of regional spatial integration, and (3) evaluate the level of efficiency in these markets. Results from the analysis indicate various forms of integration and efficiency outcomes for the sample markets. The central markets in South Africa and Botswana are characterized by significant levels of perfect integration, with higher frequency of imperfect integration with positive returns observed on the South Africa to Botswana trade route, and some occurrence of imperfect integration with negative returns observed in the opposite trade direction. For South Africa and Mozambique, trade is bidirectional and discontinuous, with very low frequency of perfect integration. Trade between South Africa and Mozambique’s Southern region generally fails to exhaust arbitrage profits, and though integrated, the market pair appears largely inefficient. South Africa and Malawi follow similar trends, although in this case perfect integration holds with higher frequency, and imperfect integration with negative return is occasionally observed from trade in the Malawi to South Africa trade route. Malawi and Mozambique’s Northern region exhibit perfect integration of a relatively high frequency, although imperfect integration with positive returns appears dominant on the Mozambique to Malawi route. Trade is bidirectional and discontinuous, predominantly in the Mozambique to Malawi direction. The market interactions between Botswana and Mozambique’s Southern region or Malawi follow a related trend exhibiting market segmentation as evidenced by the lack of trade. Efficiency holds with a fairly high frequency mostly in the form of segmented equilibrium, although significant segmented disequilibrium on the Botswana to Mozambique/Malawi route is also observed. Overall, the southern Africa maize markets considered in the sample seem to exhibit significant frequency of market integration, indicating tradability commodities and contestability of markets. Efficiency holds less frequently, although non-trivially, we observe that for those markets characterized by near continuous trade returns to arbitrage are exhausted for about 25% of the time. Often however, when trade is observed, efficiency appears to be weakened by insufficient arbitrage, possibly a result of non-cost barriers to trade (infrastructural or regulatory), imperfect information, or supply side constraints. For these markets, positive trade is also occasionally observed when arbitrage returns are negative, possibly due to contracting lags, and exchange rate fluctuations. Where trade is not observed, efficiency appears to hold with a slightly higher frequency (up to 45%), so that the lack of trade is often justified by the lack of positive arbitrage returns. Significant segmented equilibrium also seems to characterize these markets, where again the lack of trade is consistent with expected arbitrage returns. For these markets, efficiency is also occasionally compromised by insufficient arbitrage, whereby trade sometime fails to occur even when the returns to arbitrage incentives appear favorable (segmented disequilibrium). Therefore in order of frequency, we observe a high frequency of imperfect integration (regimes 3) and segmented equilibrium (regime 6), a fairly regular occurrence of perfect integration (regimes 1 and 2), and irregular occurrence of segmented disequilibrium (regimes 4) and the negative returns type of imperfect integration (regime 5). In specific markets, import prices consistently exceed domestic market prices, an inefficient outcome that appears to result from the involvement of the state in grain trade, where market conduct often is driven by non-profit objectives. These results suggest a need for policy intervention in the areas of improved productivity and access to information to takes advantage of unexploited arbitrage opportunities, and in the longer term, dealing with structural barriers to trade that prevent market entry especially where positive returns are currently observed. In some cases though, the lack of trade is an efficient outcome that probably requires no immediate policy interventions.

Suggested Citation

  • Mutambatsere, Emelly & Mabaya, Edward T. & Christy, Ralph D., 2006. "Integration and Equilibrium of Maize Markets in Southern Africa: A SADC Sub-regional Assessment," Working Papers 127056, Cornell University, Department of Applied Economics and Management.
  • Handle: RePEc:ags:cudawp:127056

    Download full text from publisher

    File URL:
    Download Restriction: no

    References listed on IDEAS

    1. McNew, Kevin, 1996. "Spatial Market Integration: Definition, Theory, and Evidence," Agricultural and Resource Economics Review, Cambridge University Press, vol. 25(01), pages 1-11, April.
    2. Gauri Prakash & Alan M. Taylor, 1997. "Measuring Market Integration: A Model of Arbitrage with an Econometric Application to the Gold Standard, 1879-1913," NBER Working Papers 6073, National Bureau of Economic Research, Inc.
    3. Barrett, Christopher B. & Li, Jau-Rong & Bailey, DeeVon, 2000. "Factor And Product Market Tradability And Equilibrium In Pacific Rim Pork Industries," Journal of Agricultural and Resource Economics, Western Agricultural Economics Association, vol. 25(1), pages 1-20, July.
    4. Spiller, Pablo T. & Wood, Robert O., 1988. "The estimation of transaction costs in arbitrage models," Journal of Econometrics, Elsevier, vol. 39(3), pages 309-326, November.
    5. Bollerslev, Tim & Chou, Ray Y. & Kroner, Kenneth F., 1992. "ARCH modeling in finance : A review of the theory and empirical evidence," Journal of Econometrics, Elsevier, vol. 52(1-2), pages 5-59.
    6. Barry K. Goodwin & Nicholas E. Piggott, 2001. "Spatial Market Integration in the Presence of Threshold Effects," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 83(2), pages 302-317.
    7. Jordan, Kenrick H. & VanSickle, John J., 1995. "Integration and Behavior in the U.S. Winter Market for Fresh Tomatoes," Journal of Agricultural and Applied Economics, Cambridge University Press, vol. 27(01), pages 127-137, July.
    8. Richard J. Sexton & Catherine L. Kling & Hoy F. Carman, 1991. "Market Integration, Efficiency of Arbitrage, and Imperfect Competition: Methodology and Application to U.S. Celery," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 73(3), pages 568-580.
    9. Penzhorn, Niels & Arndt, Channing, 2002. "Maize Markets In Mozambique: Testing For Market Integration," Agrekon, Agricultural Economics Association of South Africa (AEASA), vol. 41(2).
    10. Christopher B. Barrett, 1996. "Market Analysis Methods: Are Our Enriched Toolkits Well Suited to Enlivened Markets?," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 78(3), pages 825-829.
    11. Bollerslev, Tim, 1986. "Generalized autoregressive conditional heteroskedasticity," Journal of Econometrics, Elsevier, vol. 31(3), pages 307-327, April.
    12. Christopher B. Barrett & Jau Rong Li, 2002. "Distinguishing between Equilibrium and Integration in Spatial Price Analysis," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 84(2), pages 292-307.
    Full references (including those not matched with items on IDEAS)

    More about this item


    Crop Production/Industries;


    Access and download statistics


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:ags:cudawp:127056. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (AgEcon Search). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.