Agricultural and Food Economics

Table 1 Stationarity tests

From: Antitrust intervention and price transmission in pasta supply chain

	Jan 2005-Aug 2008		Sept 2008-Sept 2013
	ADF	KPSS	ADF	KPSS
Pasta price	−2.088	0.485^b	−1.597	0.515^b
Rising semolina price
Current	0.162	0.964^a	1.096	1.068^a
One month	0.176	0.939^a	2.652	2.029^a
Two month	0.193	0.911^a	2.680	2.035^a
Three month	0.237	0.883^a	2.690	2.038^a
Falling semolina price
Current	0.665	1.041^a	0.947	0.647^a
One month	0.254	0.698^b	1.191	0.641^b
Two month	0.741	0.821^a	0.976	0.635^b
Three month	0.743	0.938^a	1.050	1.141^a
Other costs
Labour	2.901	0.948^a	1.111	1.718^a
Energy	1.711	0.908^a	−0.515	0.463^b

In ADF test, hypothesis null is unit root while in KPSS is stationarity
^aStatistically different from zero at 1 %; ^bStatistically different from zero at 5 %
In ADF test, hypothesis null is unit root while in KPSS is stationarity

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