We do know what PPP is, that's why we know it doesn't mean much. It's based on false assumptions, and nobody even takes it to normalize for actual costs of living anymore, except for maybe you. PPP doesn't include housing prices (the largest expense of a household). PPP basically just factors out any exchange rate differential. It also doesn't include income taxes, consumption/vat taxes, which are HUGE factors.
No HDI doesn't include cancer survival rates, it just includes average lifespan. Cancer survival has nothing to do with the HDI calculation. The fact is the united states has higher cancer survival rates than europe or canada.
Since you can not educate yourself, I'll do it for you.
The main reasons why different measures do not perfectly reflect standards of living are
PPP numbers can vary with the specific basket of goods used, making it a rough estimate.
Differences in quality of goods are hard to measure and thereby reflect in PPP.
PPP calculations are often used to measure poverty rates.
The goods that the currency has the "power" to purchase are a basket of goods of different types:
Local, non-tradable goods and services (like electric power) that are produced and sold domestically.
Tradable goods such as non-perishable commodities that can be sold on the international market (e.g. diamonds).
The more a product falls into category 1 the further its price will be from the currency exchange rate. (Moving towards the PPP exchange rate.) Conversely, category 2 products tend to trade close to the currency exchange rate. (For more details of why, see: Penn effect).
More processed and expensive products are likely to be tradable, falling into the second category, and drifting from the PPP exchange rate to the currency exchange rate. Even if the PPP "value" of the Chinese currency is five times stronger than the currency exchange rate, it won't buy five times as much of internationally traded goods like steel, cars and microchips, but non-traded goods like housing, services ("haircuts"), and domestically produced crops. The relative price differential between tradables and non-tradables from high-income to low-income countries is a consequence of the Balassa-Samuelson effect, and gives a big cost advantage to labour intensive production of tradable goods in low income countries (like China), as against high income countries (like Switzerland). The corporate cost advantage is nothing more sophisticated than access to cheaper workers, but because the pay of those workers goes further in low-income countries than high, the relative pay differentials (inter-country) can be sustained for longer than would be the case otherwise. (This is another way of saying that the wage rate is based on average local productivity, and that this is below the per capita productivity that factories selling tradable goods to international markets can achieve.) An equivalent cost benefit comes from non-traded goods that can be sourced locally (nearer the PPP-exchange rate than the nominal exchange rate in which receipts are paid). These act as a cheaper factor of production than is available to factories in richer countries.
PPP calculations tend to overemphasise the primary sectoral contribution, and underemphasise the industrial and service sectoral contributions to the economy of a nation.
In addition to methodological issues presented by the selection of a basket of goods, PPP estimates can also vary based on the statistical capacity of participating countries. The International Comparison Program, which PPP estimates are based off, require the disaggregation of national accounts into production, expenditure or (in some cases) income, and not all participating countries routinely disaggregate their data into such categories.
Some aspects of PPP comparison are theoretically impossible or unclear. For example, there is no basis for comparison between the Ethiopian laborer who lives on teff with the Thai laborer who lives on rice, because teff is impossible to find in Thailand and vice versa, so the price of rice in Ethiopia or teff in Thailand cannot be determined. As a general rule, the more similar the price structure between countries, the more valid the PPP comparison.
PPP levels will also vary based on the formula used to calculate price matrices. Different possible formulas include GEKS-Fisher, Geary-Khamis, IDB, and the superlative method. Each has advantages and disadvantages.
Linking regions presents another methodological difficulty. In the 2005 ICP round, regions were compared by using a list of some 1,000 identical items for which a price could be found for 18 countries, selected so that at least two countries would be in each region. While this was superior to earlier "bridging" methods, which is not fully take into account differing quality between goods, it may serve to overstate the PPP basis of poorer countries, because the price indexing on which PPP is based will assign to poorer countries the greater weight of goods consumed in greater shares in richer countries.
Quote from bigdavediode:
Sigh. Most HDI measures use GDP at PPP. Since you're a wikipedia fan it even says that in the Wikipedia article. PPP is also referred to as "purchasing power parity" to accommodate for different costs of goods. As well, life expectancy includes things like cancer survivors.
So yes, it does include things like prices, goods and cancer survivors.
Okay, be honest now -- how many people here who don't even know what PPP is are "investors?"