This study investigates the validity of a purchasing power parity (PPP) hypothesis in the ECOWAS. Secondary data on real exchange rates, domestic inflation rates, and foreign inflation rates were sourced from the World Development Indicators of the World Bank (2018). Unit root tests, Panel unit root tests, and panel cointegration tests were used to investigate the validity of the PPP hypothesis in the ECOWAS. The study found that the PPP hypothesis is valid individually in all the ECOWAS member countries. The results from the panel unit root tests also confirm the validity of the PPP hypothesis in the ECOWAS. Specifically, the LLC with individual intercept (t = −5.97117, p < 0.0000), IPS with individual intercept (t = −3.30564; p < 0.0000), Fisher ADF with individual intercept (t = −3.43996; p < 0.0003), and Fisher PP with individual intercept (t = −5.91557; p < 0.0000) while the panel cointegration test rejects the validity of the PPP hypothesis. Therefore, the study suggests that the ECOWAS can cautiously forge ahead with the implementation of their economic integration policies and programs in the sub-region.
AgyapongD.AdamA. (2012). Exchange rate behavior: Implication for West African Monetary Zone. International Journal of Academic Research in Accounting, Finance and Management Sciences, 2(4), 215–228.
2.
AlesinaA.BarroR. J. (2002). Currency unions. Quarterly Journal of Economics, 117(2), 409–436.
3.
AloyM.BoutaharM.GenteK.Péguin-FeissolleA. (2011). Purchasing power parity and long memory properties of real exchange rates: Does one size fit all. Economic Modelling, 28(3), 1279–1290.
4.
ArizeA. C.MalindretosJ.GhoshD. (2015). Purchasing power parity-symmetry and proportionality: Evidence from 116 countries. International Review of Economics and Finance, 37, 69–85. https://doi.org/10.1016/j.iref.2014.11.014
5.
ArizeA. C.MalindretosJ.NamK. (2010). Cointegration, dynamic structure, and validity of purchasing power parity in African countries. International Review of Economics and Finance, 19(4), 755–768.
6.
BacchiocciE.FanelliL. (2005). Testing the purchasing power parity through I(2) cointegration techniques. Journal of Applied Econometrics, 20(6), 749–770.
7.
Bahmani-OskooeeM.KutanA. M.ZhouS. (2008). Do real exchange rates follow a non-linear mean reverting process in developing countries?Wisconsin, WI: The Centre for research of International Economics and the Department of Economics, The University of Wisconsin-Milwaukee.
8.
Bahmani-OskooeeM.ChangT.LeeK. (2015). Purchasing power parity in emerging markets: A panel stationarity tes with both sharp and smooth breaks. Journal of Economic Systems, 40(3), 453–460.
9.
BeckmannJ. (2013). Nonlinear adjustment, purchasing power parity and the role of nominal exchange rates and prices. North American Journal of Economics and Finance, 24, 176–190. https://doi.org/10.1016/j.najef.2012.07.005
10.
BoyerR. S. (1978). Optimal foreign exchange market intervention. Journal of Political Economy, 86(6), 1045–1055.
11.
BrissimisS. N.SiderisD. A.VoumvakiF. K. (2005). Testing long-run purchasing power parity under exchange rate targeting. Journal of International Money and Finance, 24(6), 959–981.
12.
BrodaC. (2004). Terms of trade and exchange rate regimes in developing countries. Journal of International Economics, 63(1), 31–58.
13.
ChangT.LeeC.ChouP.TangD. (2011). Revisiting long-run purchasing power parity with asymmetric adjustment for G-7 countries. Japan and the World Economy, 23(4), 259–264.
14.
CheungY. W.LaiK. S. (1993). Long run purchasing power parity during the recent float. Journal of International Economics, 34(1/2), 181–192.
15.
CheungY. W.LaiK. S.BergmanM. (2004). Dissecting the PPP puzzle: The unconventional roles of nominal exchange rate and price adjustments. Journal of International Economics, 64(1), 135–150.
16.
ChristidouM.PanagiotidisT. (2010). Purchasing power parity and the European single currency: Some new evidence. Economic Modelling, 27(5), 1116–1123.
17.
CoakleyJ.SnaithS. (2004). Testing for longrun relative purchasing power parity in Europe. Essex: Department of Accounting, Finance and Management and Essex Finance Centre, University of Essex.
18.
CopelandL. S. (2000). Exchange rate and international. UK: Pearson Education LTD.
19.
CrowderW. J. (1996). Purchasing power parity when prices are I(2). Review of International Economics, 4(2), 234–246.
20.
CushmanD. O. (2008). Long run PPP in a system context: No favorable evidence after all for the US, Germany and Japan. Journal of International Financial Markets, Institutions and Money, 18(5), 413–424.
21.
DixitA. K.StiglitzJ. E. (1977). Monopolistic competition and optimum product diversity. American Economic Review, 67(3), 297–308.
22.
DuarteA. P. (2001). Purchasing power parity: An empirical study of three EMU countries, Mimeo. Retrieved from http://www4.fe.uc.pt/gemf@fe.uc.pt
23.
FlemingM. J. (1962). Domestic financial policies under fixed and under floating exchange rates. IMF Staff Paper, 9(3), 369–379.
24.
HadriK.KurozumiE. (2008). A simple panel stationarity test in the presence of cross-sectional dependence. CCES Discussion Paper Series, Graduate School of Economics, Hitotsubashi University, Tokyo, Japan.
25.
HendersonD. W. (1979). Financial policies in open economies. American Economic Review, 69(2), 232–239.
26.
HuangC.YangC. (2015). European exchange rate regimes and purchasing power parity: An empirical study on eleven Eurozone countries. International Review of Economics and Finance, 35, 100–109. https://doi.org/10.1016/j.iref.2014.09.008
27.
HusseinA. (2015). An empirical test of purchasing power parity theory for Canadian Dollars-US Dollar exchange rate. International Journal of Economics and Finance, 7(3), 233.
28.
KenenP. B. (1969). The theory of optimum currency areas: An eclectic view. In MundellR. A.SwobodaA. K. (Eds.), Monetary problems of the international economy (pp. 41–60). Chicago, IL: The University of Chicago Press.
29.
LamontO. A.ThalerR. H. (2003). Anomalies: The law of one price in financial markets. Journal of Economic Perspective, 17(4), 191–202.
30.
LaurentiuG. V. (2013). The purchasing power parity debate: Evidence from the great financial crisis. Madrid: Grado en Economía, Facultade de Ciencias Económicas y Empresariales, Universidad Complutense.
31.
LauretiL. (2001). Purchasing power parity and integration: Empirical evidence in the mediterranean countries. Journal of Policy Modelling, 23(7), 731–751.
32.
MaW.LiH.ParkS. Y. (2017). Empirical conditional quantile test for purchasing power parity: Evidence from East Asian countries. International Review of Economics and Finance, 49, 211–222. https://doi.org/10.1016/j.iref.2017.01.029
33.
McKinnonR. I. (1963). Optimum currency areas. The American Economic Review, 53(4), 717–725.
34.
McKinnonR. I. (1981). The exchange rate and macroeconomic policy: Changing postwar perceptions. Journal of Economic Literature, 19(2), 531–537.
35.
MishraR. K.SharmaC. (2010). Real exchange rate behaviour and optimum currency area in East Asia: Evidence from generalized purchasing power parity. International Review of Financial Analysis, 19(3), 205–213.
36.
MorleyT.LoM. C. (2015). Bayesian analysis of nonlinear exchange rate dynamics and the purchasing power persistent puzzle. Journal of International Money and Finance, 51, 285–302. https://doi.org/10.1016/j.jimonfin.2014.12.003
37.
MundellR. A. (1961). A theory of optimum currency areas. American Economic Review, 51(4), 657–665.
38.
MundellR. A. (1963). Capital mobility and stabilization policy under fixed and flexible exchange rates. Canadian Journal of Economics and Political Science, 29(4), 421–431.
39.
NearyJ. P. (2004). Purchasing power parity. In McCuskerJ. J (Ed.), Encyclopedia of world trade since 1450. New York, NY: Macmillan Reference.
40.
OlagunjuM. A. (2010). An empirical examination of the purchasing power parity hypothesis in West Africa (1980–2007). Unpublished Ph.D. Thesis, Department of economics, Obafemi Awolowo University, Ile-Ife, Nigeria.
41.
OlayungboD. O. (2011). Purchasing power parity in selected sub-Saharan African countries: Evidence from Panel Unit Root Tests. Journal of Emerging Trends in Economics and Management Sciences (JATEMS), 2(4), 270–274.
42.
PakkoM. R.PollardP. S. (2003). Burgernomics: A Big MacTM guide to purchasing power parity. Federal Reserve Bank of St. Louis.
43.
PakkoM. R.PollardP. S. (1996). For here or to go? PPP and the Big MacTM. Federal Reserve Bank of St. Louis Review, 78(1), 3–21.
44.
PesaranM. H. (2007). A simple panel unit root test in the presence of cross-section dependence. Journal of Applied Econometrics, 22(2), 265–312.
45.
RamcharanR. (2007). Does the exchange rate regime matter for a real shocks? Evidence from windstorms and earthquakes. Journal of International Economics, 73(1), 31–47.
46.
RogoffK. S. (1996). The purchasing power parity puzzle. Journal of Economic Literature, 34(2), 647–668.
47.
SarnoL.TaylorM. P. (2002). Purchasing power parity and the real exchange rate. International Monetary Fund Staff Papers, 49(1), 65–105.
48.
SpenceM. (1976). Product differentiation and welfare. American Economic Association, 66(2), 407–414.
49.
SuC.ChangH.TsangyaoC. (2011). Purchasing power parity for fifteen American countries: Stationarity test with a Fourier function. International Review of Economics and Finance, 20(4), 839–845.
50.
SugimotaK. (2009). Does West Africa form an optimum currency area? A generalized PPP approach. Osaka University Knowledge Archive. Retrieved form http://ir.library.osaka-u.ac.jp/dspace/
51.
TaylorA. M.TaylorM. P. (2004). The purchasing power parity debate. National Bureau of Economics Research Working Paper No. 10607.
52.
VáclavŽ. (2010). Empirical test on the relative PPP hypothesis in new EU member states: ‘An old story old problem’. Prague: University of Economics and Management, Centre for Economic Studies, WP.
53.
YildirimD. (2017). Empirical investigation of purchasing power parity for Turkey: Evidence from recent nonlinear unit root tests. Central Bank Review, 17(2), 39–45.
54.
YusufM.NasimS. (2011). Purchasing power parity: The linkage between goods and assets markets in West African countries. Arabian Journal of Business and Management, 1(5), 1–17.
