Until 1800, China accounted for a third of world economy. In the 1880’s, the U.S. overtook China as the largest economy, a position China had for several hundreds of years. It looks like things will be returning back to “normal” in a generation’s time.

China’s growth record in the past 30 years has been incredibly remarkable, it enjoying a steady growth even during the Financial Crisis in 2008 and comprising 11 percent of global economic output in 2013. Robert Fogel, a Nobel winner in economics, forecasted in 2010 that Chinese total economic output would be $123 trillion in 2040, four times the U.S economy he predicted.

What makes China’s economy look so successful?

The first essential factor would be Chinese government making huge investment in education. Well-educated workers will turn to be highly productive workers. In China, higher education are growing steeply due to enormous state investment. In 1998, only 3.4 million students were enrolled in China’s universities. The fast change was impressive: in 2002, enrollment in higher education increased 165 percent.

Second, Chinese officials may undervalue its economic progress. In service industry, small firms often don’t report their numbers to the government and statisticians always fail to translate improvements of services’ quality into economic progress. A simple example: Chinese hospitals’ registration fee has been remaining at an unaltered ￥10 for more than a decade.

Finally, China is undergoing consumerist tendencies. In Chinese mega cities, there is already a high standard of living. At the same time, a host of policies has been set to encourage Chinese consumers’ appetite.

Everything seems to go well in China. Are there elements hindering its economic development?

“Why will growth slow? Mainly, because that is what rapid growth does.” Episodes of super-rapid growth (>6 percent) are inclined to be extremely short-lived. The median duration of a super-rapid growth episode is nine years. There are only two economies close to China’s current duration — Taiwan and Korea.

During the late 1980’s, it was widely believed that Japanese-style industrial policy, Japanese emphasis on corporate linkages and high levels of investment were keys to rapid growth. At an even broader level, it was widely believed in the early 1960’s that the Soviet Union would quite likely outstrip the United States economically.

But those forecasts were never lucky enough to be realized.

Will China be an exception? According to a prediction by The Economist, even under a moderate GDP growth rate of two percent, China will surpass the United States in 2029. Apparently, it is destined that China will lead the global economy in stead of the U.S. in few decades.

Then what will happen if China’s economy exceeds the size of America’s? Why does China’s return even matter?

A bigger economy will certainly give China global commercial domination. Fluctuations in China’s domestic demand will send ripples around the world. Market surveys will focus on China first. Leadership of international institutions will shift toward China as well. This movement includes the equivalents at that time of the United Nations, the World Bank, the International Monetary Fund, and regional development banks, etc. A more visible shift would be various headquarters moving to Beijing or Shanghai.

Geopolitically, it will necessarily alter the preeminent position that the U.S. has enjoyed since the end of the Cold War, and that Western nations have enjoyed since the 19th century.

May 2012, Facebook’s IPO turned into a huge Wall Street debacle and plumped to $17.73 that summer. Today, the tech giant’s stock price has remained around $76 since this July, doubling the company’s IPO price of $38.

CEO Mark Zuckerberg belled ringer by his mobile strategy. When the social network went public, almost all its revenue came from desktop-based ads. But with more than 500 million people consuming Facebook portably, Zuckerberg needed to transition his business.

And that transition to mobile business turned out to be smooth and successful. What has been doubled is not only its stock price, also its mobile active users — around one billion people are actively using Facebook mobile app. What’s more, the social network’s mobile ad revenue takes up more than two-thirds of its total ad revenue. Facebook’s share of total mobile advertising market is predicted to pass 12 percent in 2014, quadrupling that in 2012. That makes Facebook the biggest beneficiary of the mobile age.

Google is another big player of mobile advertising. But its mobile ad revenue accounts for only one-third of its total ad revenue and the price tag on Google’s mobile ads are much less than that of its desktop ads, according to The New York Times. From Facebook’s perspective, things look completely different: one year after its IPO, Facebook’s VP of global marketing solutions Carolyn Everson claimed that Facebook’s mobile ads cost more than desktop ads.

The new auto-playing video product is helping Facebook’s mobile monetization as well. The company wrote in a blog post that its 15-second Premium Video Ads will start playing without sound in the News Feed, and the sound will start only when users tap the video.

The company started testing premium video ads last December and introduced these ads on Facebook with a select group of advertisers this May. Facebook will sell and measure the ads “in a way that’s similar to how advertisers already buy and measure ads on TV.” This new function targets “advertisers who want to reach a large audience with high-quality sight, sound and motion.”

Facebook-owned Instagram’s performance will also charge the giant’s mobile business ahead. The photo-sharing app, with 150 million active users, only started to play ads last November. Michael Kors and Ben & Jerry’s are Instagram’s early-stage clients. Spending $1 billion on Instagram two years ago, CEO Mark Zuckerberg has every reason to expect the photo-sharing app bringing in real dollars.

This March, Instagram made a 40 million digital ad deal with Omnicom, a major holding company having a great many big-brand clients, including Nissan, AT&T and Pepsi, and looking to establish a strong relationship with the growing mobile platform. Instagram will be displaying video ads some time as well, just as its parent does.

For today’s Facebook, “Every moment is mobile.”

Ten P.M. in Pyongyang, all street lights went out. I shined a torch to penetrate the darkness. Two patrolmen spotted the light source and shouted at my direction. In a jitter, I responded in Chinese. After realizing I’m a foreign visitor, they softened their tone and let me pass by. Pyongyang citizens are not allowed to go outside at night. Another thing prohibited by North Korean government is foreign visitors exchanging for Korean People’s Won.

North Korean 5000 Won

Then how can a foreign traveler make a purchase in Democratic People’s Republic of Korea?

In the past, a separate currency for foreign visitors, also known as foreign exchange certificates, was issued by North Korea’s central bank, including two types — “red won” for visitors from socialist countries and “blue won” for visitors from capitalist countries. Foreign exchange certificates has been abandoned since 2002.

When you travel to North Korea now, in theory, you are not allowed to have North Korean won, but if you want to take something from North Korean back home, you can shop at state-run stores held in hard currency. Goods’ description labels are in English and Chinese, and goods are priced in dollar, Chinese yuan and euro there.

But that is only in theory. In fact, you can trade for Korean People’s won after street lamps going out — in the black market. I have traded Chinese Yuan for Korean People’s Won twice out of three attempts. I first traded 10 yuan ($1.6) for 10 won with two North Korean basketball players. At that time, the official exchange rate of yuan to won was 5:1, and the exchange rate in black market was about 570:1. They knew they made a killing by doing this deal with me — getting around 5,700 won by giving me 10 won.

North Korea did and does tightly control exchange rate. The iconic rate of 2.16 won (Kim Jong-il’s birthday is Feb.16) to U.S. dollar was abandoned in 2001, but the Korean government still extremely overvalues won. That’s why North Korean won in the black market is worth much less than what North Korean government wish it to be.

Then I went to a street shop in the same decoration with other shops distributed sporadically on the street. Bread displayed on the shelves comes from one single place with an identical package. Yellow neon casted dim but warm hue on the shop assistant. The moment I tried to start a conversation, she took a glance over my dangling Nikon D7 and kicked me out.

Last I stepped into a grocery store inside a residential district, which looked very different from prior street shops. A variety of commodities were set at random. I didn’t know whether I was an uninvited guest to this little store or not. But the salesman stood up when he saw me and he seemed to know he could get RMB from me. He was even willing to take the risk of being caught because I obviously offered a good deal. I bought a carton of cigarettes and 5,00 won with 50 yuan ($8.2). 

I made my “official” purchase in North Korea at a state-owned store especially running for foreign visitors — I bought an exact same carton of cigarettes as last time in 100 yuan ($16.3). They make won at least looks valuable by over-highly pricing goods to foreigners.

I’ve heard our North Korean tour guide chiding today’s China as faded socialism for dozens of times. And that was the one and only occasion when I thought “faded” was a positive word.

The Big Mac Index (BMI), was introduced by The Economist  in 1986 to “make exchange-rate theory more digestible” — tracking the over- and under-valuation of each currency against the dollar. The Big Mac Index was based on Purchasing Power Parity (PPP) Theory that a particular amount of dollars should be able to buy an identical basket of goods in each country. And that basket of goods here is the Big Mac.

If a country’s dollar price of a big mac is less than that of the United States, it means that the country’s currency is undervalued against the dollar. For example, in July 2014, $4.80 buys a Big Mac in the United States, while $2.73 buys one in China. Therefore, the yuan is undervalued by 43.13% ((2.73-4.80)/4.80*100%=-43.13%) .

McDonalds’ Big Mac is produced nearly in the same manner and held to the same standard in more than 100 countries, thus the index makes comparing many countries’ currencies possible.

The BMI has been a heated topic with one of the highest annual growth rates among other popular economic indicators since it was introduced.

Source: The Economist

In the map above,  Asia is the cheapest place to buy a big mac — Asian countries’ currencies are undervalued while European countries’ are overvalued. In 2014, the most undervalued currency is Hryvnia, undervalued by 66.09% against US dollar, and the most overvalued currency is Kroner, overvalued by 61.79%.

Source: The Economist

The table above indicates the trends for the four East Asian currencies tracked consistently from 2000 to 2014. South Korea is still in as big an upheaval as it was ten years ago. It began with a valuation 7.87% above the dollar and ended up with a valuation 16.48% below the dollar with some ups and downs in between. The yen has had a bumpy ride too.

The Big Mac Index for South Korea

After being pegged to the dollar for more than three decades, the won became a floating currency in 1997. Also in 1997, South Korea was confronted with Asian Financial Crisis and the region’s currency depreciation (other three biggest victims are Thailand, Malaysia, and Indonesia). 1997 is one of the watersheds — the won’s BMI curve had been comparatively gentle by the end of 1997 but it dramatically plunged from 1996’s 25% to 1998’s -31%. After the IMF bailing out the country in 1998, South Korea ushered in a moderate economic growth. 2008 is another watershed. Influenced by the global economic crisis, the won ‘s BMI experienced a downtrend from -7.81% to -27.55%. More evidently, the won’s BMI curve goes hand in hand with South Korea’s GDP growth, sharing a precisely synchronized rise and fall.

Hong Kong dollar and Chinese Yuan have remained relatively steady over the last 14 years. Hong Kong’s relatively smooth curve (47.83% undervalued in 2000 to 43.14% undervalued in 2014) can be explained as “Hong Kong dollar is tied to the American dollar”.

Source: The Economist

How about China? Its relative stability (52.36% undervalued in 2000 to 43.14% undervalued in 2014 with little movement in between) might be partly attributed to the steady economic growth even during the crisis. 

Source: The Economist

The Big Mac Index also reveals the rise and fall of the currency’s value under the mask of a Big Mac’s unvaried local price and exchange rate. Taking Chinese Yuan as an example, the exchange rate and the average local price of one Big Mac almost remained unchanged from 2000 to 2004, but the BMI implies that the yuan was undervalued to a varying degree during that period. The relation between BMI and RMB/dollar exchange rate has become more reasonable since 2005, because RMB/dollar exchange rate was tuned to be more “natural” by the Chinese government in 2005. This can be further explained by China’s changing currency policy.

In 1994, the Chinese government announced an initial RMB/dollar exchange rate of 8.70, which was raised to 8.28 by 1997 and remained constant until 2005. In 2005, the Chinese government modified the RMB’s exchange rate to become “adjustable,” adjusted from 8.28 to 8.11. China then halted its currency appreciation policy from 2008 to 2010 in response to the global economic slowdown, RMB being pegged to the U.S. dollar for roughly two years. In June 2010, Chinese authorities allowed the exchange rate to appreciate answering to market forces’ call.

Like any other economic indicator, the BMI has limitations. First of all, due to the different social status of fast food in different countries, the selected item may not be representative enough to see the whole picture of the country’s economy. Second, Big Macs are produced in various sizes with different ingredieants, and McDonald’s even use different commercial strategies around the world, which would result in a “non-identical basket” of goods.

With the popularity of the BMI, some similar indexes came into being. The alternative indicators based upon PPP Theory are iPad Index and iPod Index.