Do snap/early elections usually benefit those triggering them? [duplicate]

Question

I'm looking for an empirical survey (that hopefully covers more than one country) addressing the issue whether snap/early elections typically benefit those calling them, either the sole party in power or a defecting coalition member.

This shouldn't be too hard to study, but I can't seem to find any empirical papers on this topic, although I may be searching for the wrong terms. There are quite a few theoretical papers on the optimal timing of elections though... e.g. https://www.jstor.org/stable/2082980 or https://doi.org/10.1007/BF00204945 but I want an empirical survey on whether those triggering early election more often benefit from them than not.

I know Wikipedia has a page on the topic broken down by country, but it's not as systematic as one could hope. In particular countries that had many snap elections (e.g. Italy) get only a vague shrift there.

There is one 2004 book (Smith, Alastair. 2004. Election Timing. New York: Cambridge University Press.) that has studied this only in the UK an concludes that

Using data on British parliaments since 1945, the author tests hypotheses related to timing of elections, electoral support and subsequent economic performance. Leaders who call elections early (relative to expectations) experience a decline in their popular support relative to pre-announcement levels, experience worse post-electoral performance, and have shorter campaigns.

This seems to run counter to the results of the few German examples of early election, for instance. (A bit more searching found 2003 paper by the same author which seems to contain the essence of his empirical analysis.)

Answer 1

I finally found something reasonably broad in Schleiter and Tavits, "The Electoral Benefits of Opportunistic Election Timing," 2016

In this paper, we present a comparative analysis of the effect of opportunistic elections on the incumbent‘s electoral performance. The existing literature on parliamentary dissolution and election timing generates contradictory expectations about the ability of incumbent governments to benefit from strategically timed elections. We evaluate these competing hypotheses, drawing on an original dataset of 321 parliamentary elections in 27 East and West European countries, observed from 1945 or democratization to the present. In order to causally identify the effect of opportunistic election calling on incumbent‘s electoral performance, we rely on instrumental variable regression. Our results reveal that opportunistic election calling generates a significant vote share bonus for the incumbent of as much as 5.5 percentage points. This finding suggests that by timing elections strategically, governments can significantly affect how voters vote. It therefore has powerful implications for our understanding the effectiveness of elections as instruments of democracy and accountability.

Somewhat oddly they don't cite any previous systematic work

Given the number of studies on parliamentary dissolution, election timing, and political business cycles, it is surprising that there is no systematic empirical study exploring this question.

But they do cite various papers on specific events in different countries. They actually do cite the 2004 book of Smith (and his 2003 paper) but only to say that

For example, Smith (2004) points out an intriguing puzzle: if governments can control the timing of elections, why are early elections not more frequent with more incumbents taking advantage of their popularity? He then goes on to provide a thorough theoretical account of why we should not necessarily expect opportunistic elections to pay off for the incumbent. [...]

In fact, according to one of Smith‘s central hypotheses, incumbents may even systematically lose as a result of opportunistic elections. Smith (2003, 399) cites examples from the UK and France of opportunistically called elections, which resulted in significant downturns for the incumbent at the polls.

Schleiter and Tavits also cite

Grofman and Roozendaal (1994) show with data from the Netherlands that parties which precipitate government termination and new elections may not yield any electoral benefit.

which does survey all the post-war Dutch snap elections till then.

I think Schleiter and Tavits consider this country-level data be rather anecdotal because of the small sample (of elections) involved in each, in contrast to their own work.