The Giffen nature of the Irish potato was also later discredited by Sherwin Rosen of the University of Chicago in his 1999 paper "Potato Paradoxes". Rosen showed that the phenomenon could be explained by a normal demand model. Charles Read has shown with quantitative evidence that bacon pigs showed Giffen-style behaviour during the Irish Famine, but that potatoes did not. Some suggest that a number of other goods, such as cryptocurrencies like Bitcoin, might be Giffen. While the arguments are theoretically sound (i.e., they accord with Marshall's basic intuition), in each case the supporting empirical evidence has been found unconvincing. Anthony Bopp (1983) proposed that kerosene, a low-quality fuel used in home heating, was a Giffen good. Schmuel Baruch and Yakar Kanai (2001) suggested that "shochu", a Japanese distilled beverage, "might" be a Giffen good. In both cases, the authors offered supporting econometric evidence. However, the empirical evidence has been generally considered incomplete. In a 2005 article, Sasha Abramsky of "The Nation" conjectured that gasoline, in certain circumstances, may act as a Giffen good. However, no supporting evidence was offered, and evidence from the large increases in oil prices in 2008 would suggest that quantity demanded for gasoline did actually fall as a result of increased prices. Of course, the lack of evidence at the aggregate level does not rule out that the proposed goods may have been Giffen for certain groups of consumers—in particular for poor consumers.