Why Probabilities Give a Better Measure of Electoral Competitiveness

🔎 What Was Developed

A general approach to measuring electoral competitiveness for parties and governments that differs from existing proxies in two key ways. First, it estimates the actual probability that an incumbent will be re-elected—bringing the measure closer to the theoretical concept of interest. Second, it combines both pre-electoral competitiveness (uncertainty about the upcoming election outcome) and post-electoral competitiveness (uncertainty about who will form government given an election result).

🧭 How Competitiveness Is Captured

• Estimates a party- or government-level probability of re-election rather than relying on indirect proxies.
• Incorporates two distinct sources of uncertainty:
• pre-electoral: uncertainty about vote outcomes in the upcoming election
• post-electoral: uncertainty about coalition or government formation conditional on those results
• Designed to be comparable across many institutional settings and particularly suited to multiparty democracies.

📊 Where the Measure Was Tested

• 1,700 local government elections in Sweden, used to demonstrate the measure’s detailed behavior over time and its predictive power.
• 400 national elections across 34 democracies, showing the approach scales to a challenging cross-national setting.

📌 Key Findings

• The election-probability measure exhibits substantial variation over the election cycle, capturing dynamics that static proxies miss.
• The measure can be calculated accurately for a single party and for an entire government, allowing parallel analyses of party and executive vulnerability.
• It predicts actual re-election into office more effectively than any previously used measure of electoral competitiveness.

💡 Why It Matters

A probability-based measure aligns more closely with theoretical concepts of competitiveness, improves prediction of electoral outcomes, and enables meaningful comparisons across institutional contexts—especially useful for research on multiparty systems and comparative elections.