Inflation has been easing around the world. But what happens next could depend partly on the cost of diesel, a wild card that few analysts have been able to predict well. Higher gasoline prices — lit up on giant signs on streets and highways — are typically the most visible, visceral reminder of inflation to consumers. But analysts say diesel can have a bigger impact on inflation because the fuel powers trucks, industrial machinery and agricultural equipment. The prices of heating oil and jet fuel are also closely connected to…