John King - 2016 Software Development Salary Survey

In the horizontal bar charts throughout this report, we include the interquartile range (IQR) to show the middle 50% of respondents answers to questions such as salary. One quarter of the respondents has a salary below the displayed range, and one quarter has a salary above the displayed range.

A primary motivation for constructing a linear model is to clarify the relationship between salary and demographic/role-related variables when two variables are highly correlated. For example, Asian respondents tend to have less experience than other groups and also have a low median salary: $31K, about $80K less than US-based respondents. However, the model isolates the effects of the different variableswhen the model takes experience into account, the discrepancy between US and Asia salaries is halved.

We deliberately highlight effects with quotation marks to highlight a key point to keep in mind when interpreting these results: correlation does not imply causation. A classic example involves meetings: just because salary clearly rises with the weekly number of hours spent in meetings, dont expect to get a raise just by maneuvering to add meetings to your schedule! Keep in mind that the survey methodology does not support what may, intuitively, seem like reasonable assumptions of causation from even the strongest correlationstesting for causation is a difficult process at best.

We excluded managers and students from the model altogether as many of the features we think might help determine salary, such as language use, likely work differently, if at all, with these groups. We also exclude those working fewer than 30 hours per week.

One of the most basic pieces of information that has a strong effect on salary is geography. Most respondents were based in the US (61%), UK (7%), Canada (5%), Germany (4%), or Australia (2%); 26% were based in Europe. Thirty countries had at least 20 respondents in the sample, allowing for a more detailed view of salary by region. We should note that, even so, not every country is assigned a separate coefficient: coefficients are chosen for world regions (usually continents) or for countries where salaries vary greatly from those in other countries in the region. We also note that the positive and negative USD dollar amounts quoted as coefficients are only the beginning of a salary estimate: more coefficients will be added later on.

Salaries in Europe were particularly uneven, and the model assigned numerous coefficients to Europe. Northern/Western Europe tended to have higher salaries (+$17,443), while salaries in Switzerland (+$53,983) and the United Kingdom (+$25,782) were high enough to be given coefficients of their own. Developer salaries fall as we head into France (+$2,017), and further south into Spain, Portugal, Italy, Greece, and Turkey ($5,163). Eastern Europe had a coefficient of $14,804.