food expenditure, which should not be the practice. He states: "It is evident that Engel's law, rigidly interpreted is not true for particular families, for particular times, and under certain circumstances" and "The 'Engel' type of standard of living applies to no more than half of the people of the globe." Zimmerman argues that the reason for this is among other things personal tastes, family size and cultural preferences. In a review by Houthakker in 1957, the household incomes and elasticities on food, clothing and miscellaneous items are further investigated, by looking at 40 households from 30 countries. The elasticities are found to be similar to Engel's law, not equal. Based on this research, Houthakker claims that "If no data on the expenditure patterns of a country are available at all, one would not be very far astray by putting the partial elasticity at 0.6 with respect to food." Since then, researches on patterns concerning food expenditure have mainly become empirical using sophisticated statistical models. This is in part made possible due to the ever-increasing amount of data available. It is today quite common to simultaneously analyse how different types of expenditures change along with household income or total expenditure. In the 21st century there have been relatively few cross-national studies of the extent to which Engel's law remain relevant. However, a study by Richard Anker in 2011 showed "convincing evidence [...] that Engel's law continues to be relevant today across countries as well as across households within countries", but he also draws the conclusion that Engel's law today is only sufficiently strong to predict differences in food shares of countries that have large enough differences when it comes to income per capita. It is important to note that currently researchers assume an income elasticity of food being less than 1.0 (but more than 0.0), which further implies that the share of household expenditure on food decreases with rising income. Therefore Engel's law is a commonly accepted economic relationship and often referred to in the introductory sections of academic papers. The Problem The reliability of the conclusions derived from Engel’s law is non-negotiable as his law can be proved empirically as well as theoretically using today’s methods and theorems. References to Engel's law usually involve his tables from his analysis where the correlation between income and food expenditures is highlighted. The table depicts a series of various annual incomes for