Marco Portmann

• PhD
• Economist at Institute for Swiss Economic Policy (IWP)

We identify women’s revealed preferences for legislative proposals to investigate substantive representation of women. We then examine whether female or male politicians in parliament are more responsive to revealed female preferences using data on 47,527 decisions made by all 777 Swiss parliamentarians between 1996 and 2022. Holding party and cons...

Evidence on the socioeconomic effects of the protected area status of affected regions is mixed. While some studies highlight positive outcomes for these regions, others point in the opposite direction. Consequently, this study aimed to add to the discourse on whether protected area status fosters the socioeconomic development of these regions or n...

The role of electoral incentives vs. selection is ideally analyzed in a setting where individual legislators are selected to decide on policies under different electoral rules and where voter preferences on policies can be precisely measured. This is the first paper to look at such a situation. The institutional setting of Switzerland allows us to...

Zusammenfassung Die Schweiz gilt als wirtschaftlich und gesellschaftlich erfolgreich. Was steckt dahinter und was können andere Länder davon lernen? Eine verbreitete und mit moderner Ökonomie gut vereinbare Erklärung sind ihre besonderen politischen Institutionen mit direkter Demokratie und kleinräumigem Föderalismus. Tatsächlich aber hat die Schwe...

Causal estimation of the short‐term effects of tariff‐rate quotas (TRQs) on vegetable producer prices is hampered by the large variety and different growing seasons of vegetables and is therefore rarely performed. We quantify the effects of Swiss seasonal TRQs on domestic producer prices of a variety of vegetables based on a difference‐in‐differenc...

Causal estimation of the short-term effects of tariff-rate quotas (TRQs) on vegetable producer prices is hampered by the large variety and different growing seasons of vegetables and is therefore rarely performed. We quantify the effects of Swiss seasonal TRQs on domestic producer prices of a variety of vegetables based on a difference-indifference...

Direct payments represent a large share of Swiss farmers’ total household income but compliance with related requirements often entails a high administrative burden. This causes individuals to experience policy implementation as onerous. Based on a framework for administrative burden in citizen-state interactions, we test whether farmers’ individua...

We combine roll call votes and referendum decisions on identically worded legislative proposals to identify the effect of electoral rules on the way Swiss Members of Parliament (MPs) represent their constituents’ preferences. We exploit the fact that MPs in both Houses of Parliament are elected in the same electoral districts (the cantons). Yet, in...

In Switzerland, two key church institutions—the Conference of Swiss Bishops and the Federation of Protestant Churches—make public recommendations on how to vote for certain referenda. We leverage this situation to directly measure religious organizations’ power to reflect and shape human decision making. That is, using a direct measure of voters’ c...

How do politicians with past military service decide on societal issues? We explore the voting behavior of parliamentarians in the informative institutional setting of Switzerland with a conscription army. Our setting allows controlling for voter preferences and party ideology. Results show that politicians who have served in the military do not di...

We set up an opinion diffusion model with a local opinion leader, and using simulations we show the possibility of driving a significant wedge between the opinions of two groups that exhibit homophily although individuals are highly conformist. There exists an opinion gap between the group to which the opinion leader belongs and the other group. Th...

Objectives This study quantifies the quality of the median voter model (MVM) and analyzes whether personal characteristics explain legislative shirking. Methods We employ a natural measure for divergence between politicians and voter preferences by matching final roll‐call votes of politicians with referendum results. The relevance of personal cha...

Electoral systems determine the role that representatives’ party affiliations play in political representation. According to conventional expectations, party affiliation drives the behavior of representatives when they are elected under a proportional system, while majoritarian systems mute the role of party affiliation by forcing politicians to co...

While most observers feel that interest groups influence parliamentary decisions, direct evidence on this topic is scarce. Matching parliamentary votes with referendum results helps to bridge this gap. Existing research for politicians of the Swiss Lower House of Parliament suggests that the number of sectional and cause interest groups affect the...

We analyze political representation of low, middle, and high-income voters by matching their referendum choices with parliamentary decisions of legislators on the identical policy proposals. Legislators more closely represent preferences of rich voters than preferences of middle-income and poor voters.

Do politicians with a military background vote differently on military affairs? We investigate the informative institutional setting of the Swiss conscription army. Politicians who served in the military have a higher probability of accepting pro-military legislative proposals, even when controlling for party affiliations and the revealed preferenc...

Does the gender of political representatives affect the extent to which they adhere to the voter majority's preferences? By matching individual male and female representatives' votes on legislative proposals with real referendum outcomes on the same issues, we obtain a direct measure of divergence. We find that female and male representatives adher...

In parliament, individual representatives vote with a certain probability according to their constituents’ preferences. Thus, the mechanism of the Condorcet Jury Theorem can be fruitfully applied to parliamentary representation: The probability that a majority of representatives votes according to the preferences of the majority of their constitu...

It is well established that individual parliamentary representatives are less likely to decide according to the preferences of their constituency when the number of representatives per district, i.e. district magnitude, increases. However, we propose that for majority decisions of district representatives the opposite holds due to the existence of...

We identify the impact of transparency in political decision-making on the quality of political representation with a difference-in-difference strategy. The quality of political representation is measured by the observed divergence of parliamentary decisions from revealed voter preferences on identical issues. We show that full transparency of vote...

We analyze whether female or male members of parliament deviate more from voters' revealed preferences in a quasi-experimental setting. By matching female and male representatives' voting behavior on legislative proposals with real referenda outcomes on the same issues, we identify the effect of gender on divergence from the voter majority's reveal...

We reply to the comment of John Carey and Simon Hix on our original contribution entitled “District Magnitude and Representation of the Majority’s Preferences: Quasi-Experimental Evidence from Popular and Parliamentary Votes” in Public Choice 151:585–610 (2012). District magnitude does not necessarily affect deviations between political representat...

Electoral systems determine the role party affiliations play in political representation. According to conventional expectations, politicians' party affiliations should influence political representation when they are elected under a proportional system. In contrast, majoritarian systems force politicians to converge to the median position of their...

We compare the votes of parliamentary representatives and their constituents on a popular initiative that directly aimed at weakening the separation of powers in 1922 in Switzerland. We analyze whether the strength of individual ties to the public service affect the probability of voting for the initiative , holding constituents' preferences consta...

We exploit a natural measure of congruence between politicians and their constituency' bnm bnnb fgvhjuis preferences to directly quantify the extent of legislative shirking and evaluate the mechanism of the median voter model. The median voter model explains the behavior of politicians with respect to revealed preferences of their constituency abou...

We assess the effect of constituents' preferences on legislators' decisions within a quasi-experimental setting: In the Swiss referendum process, citizens and legislators reveal their preferences for legislative proposals. We match roll call votes of all Swiss legislators on 102 legislative proposals with revealed constituents' preferences on exact...

What determines political candidates’ election prospects? We match roll call votes of candidates for the majority elected upper house of parliament who were previously in the lower house with the preferences of their constituency as revealed in referenda. Thereby, we obtain a unique and direct measure of past congruence. Politicians who better repr...

We explore the quality of political representation of constituents’ preferences for budgetary decisions within a quasi-experimental setting. In the Swiss referendum process, constituents reveal their preferences for budgetary proposals which are either expected to increase or decrease public debts. We match individual politicians’ voting behavior o...

We analyze whether female or male members of parliament adhere more closely to citizens’ revealed preferences with quasi-experimental data. By matching individual representatives’ voting behavior on legislative proposals with real referenda outcomes on the same issues, we identify the effect of gender on representatives’ responsiveness to rev...

We analyze the effect of constituents’ preferences on legislators’ decisions within a quasi-experimental setting: In the Swiss referendum process, constituents and legislators vote on policy proposals and thus reveal their preferences. We match roll call votes of all legislators on 118 legislative proposals with revealed constituents’ preferences o...

We match individual senators’ voting behavior on legislative proposals with 24 real referendum decisions on exactly the same issues with identical wording. This setting allows us to evaluate the median voter model’s quality with revealed constituents’ preferences. Results indicate a limited explanatory power of the median voter model: It explains 1...

Electoral systems determine the role party affiliations play in political representation. According to conventional expectations, politicians’ party affiliations should influence political representation when they are elected by proportional representation. In contrast, majoritarian systems force politicians to converge to the median position of...

Representatives have more effective incentives to cater to the preferences of the majority of citizens when they are elected in districts with few rather than many seats. We investigate this hypothesis empirically by matching Swiss members of parliament’s voting behavior on legislative proposals with real referendum outcomes on the same issues for...

When moving from a plurality rule to a proportional system, members of national parliament have more incentives to diverge from the median voter's preferences. We match voting behavior concerning legislative proposals of Swiss members of parliament with real referenda outcomes on the same issues for the years 1996 to 2009. This quasi-experimental d...