The Phillips curve is assumed to be upward-sloping; that is, if economic conditions improve and we move to the right along the Phillips curve, the inflation rate will increase.
Clearly, fluctuations in food prices are largely determined by supply and demand factors inherent to these markets, such as the pace of world economic activity, demographic changes, the implications of higher income levels in some countries for eating habits, climate related factors, and the availability of water and arable land, among others.