品牌均势（Brand Parity）

parity（胎次）

无抵补利率平价条件(term of uncovered interest-rate parity)

购买力平价(urchasing power parity)

购买力平价和利率平价理论(theory of purchasing power parity & theory of interest-rate parity)

It is nearly 25 years since The Economist cooked up the Big Mac index. It was devised in September 1986 as a fun way to explain "purchasing-power parity", by comparing the prices of hamburgers in different countries. But burgernomics has since provided serious food for thought. Some economists think the Big Mac index has been surprisingly accurate in predicting long-run movements in exchange rates. It has also provided a few hot tips (and some half-baked ones) for investors.
When the euro was launched in 1999, almost everybody reckoned it would immediately rise against the dollar. But the Big Mac index suggested that the euro was already overvalued. Soros Fund Management, a prominent hedge fund, later said that it sniffed at the sell smell coming from the Big Mac index, but resisted the temptation to bite. It was cheesed off when the euro promptly fell. Today, our burger barometer suggests that the euro is again overvalued against the other main currencies, and it highlights the euro area’s internal problems, showing that Greece, Italy, Portugal and Spain have lost competitiveness relative to Germany.
Burgernomics is also a handy check on whether governments are understating inflation. It supports claims that Argentina has been cooking the books: over the past decade, Big Mac prices there have, on average, risen by well over ten percentage points more each year than the official consumer-price index—a far bigger gap than in any other country. But bingeing on burgernomics can be unhealthy. American politicians cite the Big Mac index as proof that the yuan is massively undervalued. It is true that burgers are cheap in China, but so they should be in all emerging economies, because wages are much lower. If the index is adjusted for GDP per person, it shows that the yuan is now close to its fair value against the dollar.
Studies suggest that the Big Mac index fairly closely tracks the purchasing-power-parity rates calculated by more sophisticated methods. Yet whereas those fancier techniques require researchers to gather thousands of prices in each country and take two years to produce, the Big Mac index relies on a single product, so the results are almost instant.
Official economic statistics are published only after a lag and are subject to big revisions. This explains the popularity of some quirky but timely indicators. When Alan Greenspan was chairman of the Federal Reserve, he monitored several unusual measures. One favourite, supposedly, was sales of men’s underwear, which are usually pretty constant, but drop in recessions when men replace them less often. The Old Lady of Threadneedle Street is perhaps too prim to inspect men’s underpants. Instead, the Bank of England tracks data on internet searches for telltale terms. It has, for example, found that the trend in searches for "estate agents" can be a predictor of house prices.
What can we learn about the Big Mac index according to Paragraph 1

A:It predicts the changes in Big Mac prices all over the world. B:It shows purchasing-power parity based on burgers’ prices. C:It provides investors with absolutely reliable information. D:It can help people to predict food prices.

无抵补利率平价条件(term of uncovered interest-rate parity)