peanut butter and bread

"the price of bread did not vary; its weight did. roughly speaking, variable weight was the general rule throughout the western world. the average weight of bread sold in the bakers' shops in saint mark's square or on the rialto in venice varied in an inverse ratio to the price of grain...regulations published in cracow in 1561, 1589, and 1592 indicate the same practices; unvarying prices and variable weights."
"the structures of everyday life: civilization and capitalism 15th-18th century. volume 1" fernand braudel. p139

i know this has nothing to do with gardening and i was unsure which blog to post this in...but it is food related...and it is related to an industrial food system that is capitalist at heart and has to turn a profit to keep shareholders happy, even in difficult times...since this project is meant to stand in contrast to industrial food i thought, in the end, that it was germane to the underlying philosophy so i put it here ( and i am much less likely to go off on a terminal rant in this blog )...these three brands of peanut butter sell at the local supermarket for prices that can be covered by 10 ( wow..there is no "cent" sign on this keyboard..are cents obsolete?) cents...pretty standard pricing industry-wise but the jars are significantly different...the fisher's jar has a reasonably flat bottom...the skippy and planter's jars have a "punt" in the bottom...a concave structure that adds strength to champagne bottles but serves to lessen the amount of peanut butter in the jars...the skippy and planter's jars have 16.3 ounces, the fisher's 18 ounces...the fisher's jar is also a quarter inch bigger in diameter...so, like the fourteenth and fifteenth century european bread makers, peanut butter producers ( and, i'll wager other food producers ) are varying the quantity of goods provided, not the price...a long tradition of sleight of hand...i am curious to know what fifteenth century bakers did to make their loaves appear larger than they were...or was that more an issue of government fiat than marketing manipulations?