Dancing in the Moonlight? MPs with Outside Interests Vote Less 

 In Britain (and many other democracies) Members of Parliament often have "Outside Interests" and draw extra income from paid directorships, consulting gigs, or journalistic work. There has been plenty of controversy about MPs having such outside interests ranging from possible ethical issues to concerns over possible impact on MPs' legislative behavior. One concern is that MPs may be less effective as a representative if they "moonlight" from their Westminster jobs.  

 In a recent  paper  about the financial returns to serving in the House of Commons, Andy Eggers and I consider the relationship between outside interests and MPs' vote attendance (the percent of eligible votes personally attended or told) for the 2005-2007 period. We find that for both the Conservative and the Labour party, MPs with at least one (self-)reported outside interest (directorships, consultancies, and work in journalism) attended fewer votes compared to MPs with no outside interests; attendance rates are around 4-6 percentage points lower and the differences are all significant at conventional levels. The results are summarized in the jittergrams below (we excluded MPs that hold office as minister, speaker, whips, and chairman of standing committees who are not allowed to vote).  

  
    

  
The exception are directorships for Labour MPs where we cannot reject the null 
of no difference. We also find no such difference for MPs when comparing those with and 
without regular employment (such as work as a barrister, medical doctor, etc.).  

 There are obviously several other factors that may contribute to low attendance rates such as absence on constituency business, illness, paternity/maternity leaves, etc., but overall the results do suggest that outside interests distract MPs from their legislative work. This finding is also consistent with earlier work by Muller (1977), who found that sponsored Labour MPs were more active than other MPs on issues close to the interests of their sponsors (e.g. mining or railway issues), but that on the whole they were less active members of Parliament, participating in question time, standing committees, and debates far less than non-sponsored members. 

 If this whetted your curiosity you can analyze the voting data for yourself at  publicwhip .