International migrants comprise only a small fraction of all humans on Earth. Considering the small shares that migrate, it is easy to understand that these may potentially be very different from those who do not. The fewer the migrants are, the more different they are likely to be. (It is a mathematical fact that a small group may potentially differ more— in any sense— from the remaining population the smaller it is. The average height in a “group” consisting only of the world's tallest person is a simple illustration of this fact.)

This chapter is devoted to describing the migrants and their decision to migrate: the factors that are most decisive for the decision, and hence who is more likely to make a positive decision and become a migrant. The chapter title's plural form underscores one of the main themes of the chapter as well as of the book: migration is not one singular and easily summarized phenomenon where one type of person migrates for one reason. It is a vast array of things, where different circumstances in different places create different migrants.

How well-informed are migration decisions?

Migrants are thus likely to be different in some or many ways from nonmigrants. And this may be in different ways for different migrant flows, and also for different migrants in the same flow. Historian John Gould wrote about the Europeans who moved to North America before the advent of transatlantic steam traffic in the 1860s, that the “appalling conditions [on the ships] deterred all but the most resolute, the most desperate, and the most ignorant of emigrants.”

The word “ignorant” was probably a quite fitting description of a large share of these early migrants, who had few ways of obtaining more detailed and reliable information about America than the rumors that it was much easier to make a living there. Considering the radical change— for life— that these migrants decided to make based on such scarce information, a greater willingness to accept risk is probably also a characteristic that set many migrants apart from non-migrants in this period, as well as in much of both earlier and later history.

Later on, as migrants— and hence letters to relatives in their home countries— became more numerous, knowledge about America also increased considerably among potential later European migrants.