SIPA at Columbia
Thomas Groll

home Research Interests

My main academic interests relate to topics in public economics, industrial organization, political economics, and applied microeconomics. Current research projects focus on the implications of
  • Growing activities by commercial lobbyists as intermediaries
  • Optimal lobbying strategies of resource provision and targeting 
  • Resource constraints on lobbying activities and political outcomes
  • Financial regulation, delegation of oversight and lobbying actitivities
  • Lobbying activities on electoral competition

Working Papers

Abstract  We consider the strategic considerations inherent in legislative subsidies and develop an informational lobbying model with costly policy reforms. In contrast to other models of informational lobbying we focus on the implications of a policymaker's and a lobby's resource constraints for lobbying activities. We allow both a policymaker and a lobby to gather information, and each can either fund or subsidize policy making. Our analysis highlights the strategic manipulation of legislative subsidies that arises endogenously and depends on which resource constraints bind, the policymaker's prior beliefs, the salience of policy, and expertise of the policymaker and the interest group. Our analysis illustrates when an interest group may lobby a friendly, hostile, or undecided policymaker and when a resource constrained policymaker may gather own information. Our analysis also highlights how an interest group may strategically waste resources and when informational lobbying and transfers are complements, substitutes, or independent.

Current version: April 2017.
Supplemental .nb files: upon request.
Abstract  We study lobbying in a setting in which decision-makers share resources in a network. Two opposing interest groups choose which decision-maker they want to target with their resource provision, and their decision depends on the decision-makers' ideologies as well as the network structure. We characterize the lobbying strategies in various network settings and show that a higher resource flow as well as homophily reinforce decision-makers' ideological bias. We highlight that competing lobbyists' efforts do not neutralize each other and their payoffs and competitive advantages depend on the networks they face. Our findings are consistent with empirically established lobbying activities.

Current version: August 2016.
Supplemental: Supplemental Appendix

Revise & Resubmit

Abstract  Using explore the determinants of U.S. financial market regulation with a formal model of the policy-making process in which government regulates financial risk at both the firm and systemic levels, and test these predictions with a novel, comprehensive data set of financial regulatory laws enacted since 1950. We find that political factors impact Congress' decision to delegate regulatory authority to executive agencies, which in turn impacts the stringency of financial market regulation. In particular, Congress delegates authority to regulators when: 1) policy preferences between Congress and executive officials become more similar; 2) Firms' investment risks become more uncertain; and 3) Congress’ concerns about a bailout are greater. As a result, financial markets are more heavily regulated when firm-specific and systemic risks are uncertain. However, when inter-branch preferences differ or perceived systemic risk is low, Congress may allow risky investments to be made that, ex post, it wished it had regulated.

Current version: November 2016.
Supplemental .nb files: upon request.

Abstract  This paper analyzes the effective regulation of commercial lobbying activities and focuses on the endogenous choice of regulatory institutions. The analysis uses a model of commercial lobbying in which citizens hire lobbyists to present policy matters on their behalf, and policymakers announce political access rules to induce citizens and lobbyists to engage in information acquisition and make financial contributions. The distribution of private costs and public informational benefits from commercial lobbying can explain why commercial lobbying is widely employed, but may not be socially efficient, and may lack public support. I derive the institutional conditions under which a market outcome can be first-best as well as the conditions under which a first-best institution will or will not be self-stable. One result is that current lobbying regulation may fail to be effective: unable to limit lobbyists' and policymakers' incentives to substitute financial contributions for socially beneficial information acquisition. The analysis highlights the necessity to monitor information transfers as well as financial transfers to construct effective regulatory instruments. Additional results explain why endogenous reforms that regulate lobbying activities may or may not occur.

Current version: March 2013.


  • Repeated Lobbying by Commercial Lobbyists and Special Interests joint with Christopher J. Ellis - Economic Inquiry, forthcoming.
    [Pre-publication version]
Abstract  Developing a lobbying model of repeated agency, we explain previously unexplained features of the real-world lobbying industry. Lobbying is divided between direct representation by special interests to policymakers, and indirect representation where special interests employ professional intermediaries called commercial lobbyists to lobby policymakers on their behalf. Our analytical structure allows us to explain several trends in lobbying. For example, using the observation that in the U.S. over the last 20 years policymakers have spent an increasing amount of their time fundraising as opposed to legislating, we are able to explain why the share of commercial lobbyist activity in total lobbying has risen dramatically and now constitutes over 60% of the total. The key scarce resource in our analysis is policymakers' time. Policymakers allocate this resource via implicit repeated agency contracts which are used to incent special interests and commercial lobbyists to provide a mix of financial contributions and information on policy proposals. These implicit agency contracts solve both an information problem in the presence of unverifiable policy information and a contracting problem in the absence of legal enforcement. These repeated relationships, that are often described using the pejorative term cronyism in the popular press, may in certain circumstances be welfare improving.

Supplemental Appendix
Previous working paper: CESifo #5809.

Abstract  In this paper we present a model of the behavior of commercial lobbying firms (such as the so-called K-Street lobbyists of Washington, D.C.). In contrast to classical special interest groups, commercial lobbying firms represent a variety of clients and are not directly affected by policy outcomes. They are hired by citizens, or groups of citizens, to act as intermediaries on their behalf with policymakers. In our analysis we address two basic questions; what tasks are commercial lobbying firms performing, and what are the implications of their existence for social welfare? We answer the first part of this question by proposing that commercial lobbying firms possess a verification technology that allows them to improve the quality of information concerning the social desirability of policy proposals. This gives policymakers the incentive to allocate their scarce time to commercial lobbying firms. Essentially, it is this access to policymakers that commercial lobbying firms sell to their clients. To address the question of social welfare we construct a simple general equilibrium model that includes commercial lobbying firms, and compare the equilibrium obtained under market provision of lobbying services to the first-best optimum. We find that the market level of lobbying services can be socially either too large or too small, and characterize when each will be the case.

Supplemental Appendix
Previous (longer) working paper: CESifo #4110.
Abstract  An income growth pattern is pro-poor if it reduces a (chosen) measure of poverty by more than if all incomes were growing equiproportionately. Inequality reduction is not sufficient for pro-poorness. In this paper, we explore the nexus between pro-poorness, growth and inequality in some detail using simulations involving the displaced lognormal, Singh-Maddala and Dagum distributions. For empirically relevant parameter estimates, distributional change preserving the functional form of each of these 3-parameter distributions is often either pro-poor and inequality reducing, or pro-rich and inequality exacerbating, but it is also possible for pro-rich growth to be inequality reducing. There is some capacity for each of these distributions to show trickle effects (weak pro-richness) along with inequality-reducing growth, but virtually no possibility of pro-poorness for growth which increases overall inequality. Implications are considered.
Previous (longer) working paper: ECINEQ #2011-214.

Other Writings
  • Big Data and the Regulation of Banking and Financial Services joint with Sharyn O'Halloran, Sameer Maskey, Geraldine McAllister, David Park - Banking & Financial Services Policy Report: A Journal on Trends in Regulation and Supervision, vol. 34 (12), 2015. 
    (contact me for a copy)
  • Modern Lobbying: A Relationship Market joint with Maggie McKinley - CESifo DICE Report: Journal for Institutional Comparison, vol. 13 (3), 2015.
  • Dynamic Commercial Lobbying joint with Christopher J. Ellis - CESifo Working Paper 4114, 2/2013.

Works in Progress
  • Your own Lobbyists or Hired Guns? Theory and Evidence with Christopher J. Ellis.
  • Lobbying and Delegation with Sharyn O'Halloran.
  • Commercial Lobbying and Electoral Competition with Christopher J. Ellis.