Daina Chiba

Publications

  • 5. A Copula Approach to the Problem of Selection Bias in Models of Government Survival [Show details]
        (with Lanny Martin and Randy Stevenson)
       Forthcoming at Political Analysis
    • Abstract
      Recent theories of coalition politics in parliamentary democracies suggest that government formation and survival are jointly determined outcomes. An important empirical implication of these theories is that the sample of observed governments analyzed in studies of government survival may be nonrandomly selected from the population of potential governments. This can lead to serious inferential problems. Unfortunately, current empirical models of government survival are unable to account for the possible biases arising from nonrandom selection. In this study, we use a copula-based framework to assess, and correct for, the dependence between the processes of government formation and survival. Our results suggest that existing studies of government survival, by ignoring the selection problem, significantly overstate the substantive importance of several covariates commonly included in empirical models.
    • Manuscript in PDF
    • Publisher link
    • Supplementary files
    • Replication materials (IQSS Dataverse)
  • 4. Every Story Has a Beginning, Middle, and an End (But Not Always in That Order): [Show details]
        Predicting duration dynamics in a unified framework
        (with Nils Metternich and Michael Ward)
       Conditionally accepted at Political Science Research and Methods
    • Abstract
      There are three fundamental duration dynamics of civil conflicts: Time until conflict onset, conflict duration, and time until conflict recurrence. Theoretical and empirical models of war usually focus on one or at most two aspects of these three important duration dynamics. We argue that duration forecasting of conflict needs to incorporate all three conflict dynamics as unobserved factors might impact on all three of these dynamics. We present a new split-population seemingly-unrelated duration estimator that treats pre-conflict duration, conflict duration, and post-conflict duration as interdependent processes thus permitting improved predictions about the onset, duration, and recurrence of civil conflict. Our findings provide support for the more fundamental idea that prediction is dependent on a good approximation of the theoretically implied underlying data generating process. In addition, we account for the fact that some countries might never experience these duration dynamics or become immune after experiencing them in the past.
    • Manuscript in PDF
  • 3. Major Powers and Militarized Conflict [Show details]
       (with William Reed and Carla Martinez Machain)
       Journal of Conflict Resolution, Vol. 58, No. 6 (Sep., 2014), pp. 976-1002.
    • Abstract
      This paper attempts to answer the question of why major powers engage in more active foreign policy behaviors than minor powers. It does so by comparing two explanations for the increased conflict propensity of major powers. The first explanation focuses on major powers' observable capabilities, while the second stresses their different behavior. We incorporate both into an ultimatum model of conflict in which a state's cost of conflict consists of both observable and behavioral components. Using data from the period from 1870 to 2001, we empirically illustrate the observable and behavioral differences between major and minor powers. We then utilize a decomposition model to assess the relative significance of the two explanations. The results suggest that most of the difference in conflict propensity between major and minor powers can be attributed to observable differences.
    • Manuscript in PDF
    • Publisher link (journal subscription required)
    • Replication materials (IQSS Dataverse)
  • 2. Institutional Opposition, Regime Accountability, and International Conflict [Show details]
       (with Songying Fang)
       Journal of Politics, Vol. 76, No. 3 (Jul., 2014), pp. 798-813.
    • Abstract
      Can international organizations constrain a leader's behavior during a military crisis? Existing studies have shown that joint membership in international organizations reduces the likelihood of dispute initiation; however, whether institutional opposition can prevent an ongoing conflict from escalating has yet to be investigated. We develop and test a theory of how domestic politics provides a mechanism through which international organizations can reverse the course of a military crisis. The argument leads to the hypothesis that more accountable regimes are less likely to escalate military crises when an international organization opposes their actions. We test the hypothesis with an analysis of territorial disputes from 1946 to 1995. We find that while neither institutional opposition nor the degree of regime accountability independently reduces the tendency for a country to escalate a conflict, the joint effect of the two does.
    • Manuscript in PDF
    • Publisher link (journal subscription required)
    • Online Appendix
    • Replication materials (IQSS Dataverse)
  • 1. Decomposing the Relationship Between Contiguity and Militarized Conflict [Show details]
       (with William Reed)
       American Journal of Political Science, Vol. 54, No. 1 (Jan., 2010)  
    • Abstract
      It is well known that the majority of militarized conflicts and wars have been fought by neighbors. Yet, much remains to be learned about the relationship between shared borders and militarized conflict. This paper decomposes the effects of territorial contiguity into ex ante "observable" and "behavioral" effects. It provides powerful empirical evidence for the claim that although neighbors are more likely to experience conflict because of ex ante differences in observable variables such as economic interdependence, alliance membership, joint democracy, and the balance of military capabilities, most conflicts between neighbors occur because of differences in how neighbors and nonneighbors respond to the observable variables.
    • Publisher link (journal subscription required)
    • Replication materials (IQSS Dataverse)

Working Papers

  • Peaceful Territorial Transfers and Third Party Conflict [Show details]
       Under Review    (with William Reed)
    • Abstract
      This paper examines the relationship between peaceful territorial transfers and the risk of conflict with third party states. A model is analyzed that shows how peaceful territorial transfers can create a bargaining problem with a third party that is interested but uninvolved in the transfer of the territory. This happens in many cases because the state receiving the territory is also imparted with a significant increase in their bargaining leverage with the third party. Historical data on peaceful territorial transfers is brought to bear on hypotheses developed from the theoretical model, and the empirical results are remarkably strong and illustrate third party conflict is an important and unintended consequence of peaceful territorial change.
    • Manuscript in PDF
  • Procuring Peace after Prolonging War: [Show details]
        International Organizations and the Durations of International Conflict and Post-conflict Peace
    • Dissertation Chapter [PDF]
    • Abstract
      How do international organizations (IOs) influence states' conflict behavior in the absence of centralized enforcement? This study develops and tests an argument about how IO membership affects the enforcement problems states face in the aftermath of militarized conflict. It maintains that joint membership in IOs that explicitly promote peaceful settlement of disputes improves enforcement conditions by increasing the costs of cease-fire violation in the long run. As a result, these IOs make a cease-fire more durable once the disputants agree to stop fighting. However, precisely because they expect longer peace after conflict, the member states have incentive to adopt tougher bargaining positions during conflict, causing a delay in reaching a cease-fire. A survival analysis that recognizes the interdependence between the durations of conflict and subsequent peace demonstrates that IO membership lengthens the durations of conflict and subsequent peace.
    • Won the 2012 Dina Zinnes Award for the best graduate student paper presented at 2011 ISA Annual Convention.
  • The Strength of Cease-fire Agreements and the Duration of Postwar Peace [Show details]
    • Dissertation Chapter [PDF]
    • Abstract
      Do stronger cease-fire agreements keep peace longer after war? Although there are theoretical reasons to expect that stronger agreements promote durable peace, the extant empirical research provides mixed support for this expectation. This paper reexamines this argument empirically, addressing two inferential problems overlooked in the past studies. First, since the strength of cease-fire agreements is endogenous to the baseline prospect for peace, I employ a copula-based two-stage estimation that explains agreement strength and peace duration jointly. Second, I allow the effect of agreement strength to vary over time. This is important because agreement strength matters little right after the war, for there exists a rough consensus among the ex-belligerents about the likely outcome of a next war. As time passes, however, the effect of agreement strength will start to show because there will be a greater chance that some exogenous shocks distort this consensus. Analyzing the duration of postwar peace from 1914 to 2001, I demonstrate that stronger cease-fire agreements indeed promote more durable peace.
  • Careful Commitments: Democratic States and Alliance Design [Show details]
       (with Jesse C. Johnson and Brett Ashley Leeds)
    • Down for revision
    • Abstract
      Some scholars have argued that leaders of democratic states experience high costs from violating past commitments, including military alliances. We argue that because democratic leaders foresee the costs of violation, they are careful to design agreements that commit them to intervene in conflicts only under specific conditions, or that provide them flexibility to choose their actions at a later date. We evaluate our argument by analyzing the design of alliance treaties signed by countries of the world between 1815 and 2003. The results of the analysis reveal that the design of alliances signed by democracies tends to be different in predictable ways from the design of those signed by non-democracies. Specifically, we find that alliances formed among a larger proportion of democratic states are more likely to include obligations for future consultation rather than precommitting leaders to active conflict, and defense pacts formed among a larger proportion of democratic states are more likely to specify limits to the conditions under which member states must join their partners in conflict. This research enhances our understanding both of the effects of domestic institutional structures on international relations, and of the design and effects of international agreements.
  • What Do Colony Indicators Indicate in Foreign Aid Models? [Show details]
        (with Tobias Heinrich)
    • Down for revision
    • Abstract
      It has long been shown that donors of foreign aid provide much more foreign aid to former colonies than to other states. However, we know relatively little about why this is the case, and the use of the corresponding colony-indicator variable is rarely justified theoretically. This paper offers a thorough examination of the relationship between colonial history and the receipt of foreign aid. Starting with a formal model that sees aid as a payment for policy concessions a la Bueno de Mesquita and Smith (2009), we arrive at two possible classes of explanations for why former colonies receive more aid. 1) Due to the colonial history, former colonies tend to have observable characteristics typically associated with greater aid inflow. 2) Donors may attach greater salience to policy concessions from former colonies than that from non-colonial recipients that have similar observable characteristics. Both explanations expect a positive relationship between colonial history and the foreign aid inflow. Using a decomposition approach from labor econometrics, we disentangle the observational equivalence and assess the relative merits of these two views. Our results show that about 66-73 % of the colony effect on foreign aid stems from the greater saliency that donors give to former colonies' policy concessions.

Resources

  • LATEXresource for Rice students & scholars
    • I created some Beamer style files and presentation examples (slide and poster) for Rice students and scholars.
    • Link to the RiceBeamer page
  • Presenting statistical results
    • I ran a workshop for grad students and faculties in the political science department about how to present statistical results using R and Stata in combination. You can download this archived directory (zip, 45 MB) that contains the handout, an accompanying R code, Stata do-file, data, etc., necessary to replicate all the figures and tables I talked about in the workshop. Topics I covered include:
    • Producing publication-quality regression tables efficiently (Stata)
    • Calculating and plotting substantive effects (R) ··· Example 1, Example 2
    • Plotting descriptive statistics (R) ··· Example 3
    • Plotting regression coefficients (R) ··· Example 4
    • For more of these graphs, go to Using Graphs Instead of Tables website by Jonathan Kastellec and Eduardo Leoni.
  • R utilities for clustered standard error
    • As a quantitative IR researcher, I have seen many examples utilizing the following two estimation options of Stata -- , robust and , cluster(dyad). These frequently-used options are supposed to give us the "corrected" standard error estimates when observations are suspected to be interdependent within analysis unit (e.g., dyad) and/or distribution is not identical (i.e., errors are heteroskedastic). The good news is that the Stata implementation of these techniques is quite easy. The bad news is that this is a very handy tool for "star-gazing" -- an act of searching for statistical significance (stars!) by trying a bunch of different specifications and statistical patches without paying careful attention to the causal mechanism behind the data-generating process. Robust and/or clustered standard errors sometimes make your p-values much smaller, causing otherwise statistically insignificant coefficients to be very significant. Well, there is nothing inherently wrong about reporting robust standard errors instead of conventional ones. But, you should not use them just because this is the only way to have stars for your favorite variables. And you should not use them without understanding what they really mean.
    • So..., what exactly do we mean by standard error being "robust"? In what sense do we say that the estimation uncertainties are "adjusted for possible non-independence within dyad?" And, more (or less) importantly, how do we execute them on R? I suppose some step-by-step examples might help us gain intuition behind these methods, and will get us ready to implement the techniques on our own.
    • logit..., cluster(dyad) ··· Example R code to calculate clustered s.e. for a typical logit model of interstate disputes.
    • logit..., robust ··· Example R code to calculate robust s.e. for a typical logit model of conflict.
    • Sweave output (pdf) of the above two. This is generated by running the Sweave source (.Rnw) on R and then typesetting the tex output (.tex) on LATEX.
  • R utilities for selection model estimation
    • The R code below estimates the Heckman's probit model in R.
    • HeckmanProbit.R
  • R utilities for copula estimation
    • The R code below contains functions that transform the dependency parameter (θ) of the Frank's bivariate copula into some common measures of correlation. The function frank.rho() outputs the Spearman's ρ and the function frank.tau() outputs the Kendall's τ. The calculation involves numerical integration as a part of the Debye function.
    • ThetaToRho.R


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About

I am a lecturer (assistant professor) in the Department of Government, University of Essex. My research interests encompass the areas of militarized conflict, international institutions, and political methodology. My dissertation reflects all of these interests. In particular, my dissertation studies the effect of international institutions on the duration and recurrence of violent conflict, and I have developed new statistical methods to address challenging inferential problems that I have encountered during the research.


News

  • August 2014: A new draft of "Peaceful Territorial Transfers and Third Party Conflict" is up.
  • August 2014: "A Copula Approach to the Problem of Selection Bias in Models of Government Survival" is accepted at PA.
  • Feb 2014: "Institutional Opposition, Regime Accountability, and International Conflict" is accepted at JoP.
  • Site Design