As I mentioned recently, German convenience kiosks don't have bulletproof glass, because there's almost no stranger-on-stranger violent crime in Germany.
Meanwhile America, according to a recent study, is the most heavily-guarded nation on earth right now, with more private security guards than schoolteachers. The authors say income inequality is one reason for this:
Note that, in 1979 (shown by the pink dot), the United States was less unequal and employed less guard labor. In the graph, inequality in income takes account of payment of taxes and receipt of government transfers such as Social Security. (We measure inequality by the Gini index, a measure that varies from 0 for complete equality — that is, if all families have the same income — to a value of 1 if a single person has all of the income.) The data shown are the most recent for all nations on which comparable measures of inequality and guard labor are available.
For the same countries, guard labor is also more common where those starting out in life face a sharply tilted playing field, such as America, Britain and Italy. These are countries in which the income of a father is a good predictor of the income of his adult son. The countries with the least guard labor are those in which there is greater equality of economic opportunity by this measure: These are Denmark and Sweden, countries in which knowing the father’s income does not enable a very accurate guess of the son’s income when he grows up.
...[T]he correlation evident in the graph could be evidence that economic disparities push nations to devote more of their productive capacity to guarding people and property. Fear and distrust of one’s neighbors and fellow citizens fuel the demand for guard labor. Economic disparities can contribute to both. Among the countries shown, a common measure of distrust of strangers is strongly correlated with both the guard-labor fraction and inequality.
Social spending, also, is strongly and inversely correlated with guard labor across the nations shown in the graph. There is a simple economic lesson here: A nation whose policies result in substantial inequalities may end up spending more on guns and getting less butter as a result.